{"id":100598,"date":"2026-09-04T21:18:11","date_gmt":"2026-09-04T13:18:11","guid":{"rendered":"https:\/\/www.wsisp.com\/helps\/100598.html"},"modified":"2026-09-04T21:18:11","modified_gmt":"2026-09-04T13:18:11","slug":"%e5%89%8d%e7%ab%af%e5%9f%ba%e7%a1%80-javascript%ef%bc%88%e5%9f%ba%e7%a1%80%e8%af%ad%e6%b3%95%ef%bc%89%ef%bc%88%e4%b8%8a%e7%af%87%ef%bc%89","status":"publish","type":"post","link":"https:\/\/www.wsisp.com\/helps\/100598.html","title":{"rendered":"\u524d\u7aef\u57fa\u7840\u2014\u2014JavaScript\uff08\u57fa\u7840\u8bed\u6cd5\uff09\uff08\u4e0a\u7bc7\uff09"},"content":{"rendered":"

\u76ee\u5f55<\/p>\n

\u521d\u8bc6JavaScript<\/p>\n

JavaScript\u662f\u4ec0\u4e48<\/p>\n

\u53d1\u5c55\u5386\u53f2<\/p>\n

JavaScript\u548cHTML\u548cCSS\u4e4b\u95f4\u7684\u5173\u7cfb<\/p>\n

JavaScript\u8fd0\u884c\u8fc7\u7a0b<\/p>\n

JavaScript\u7684\u7ec4\u6210<\/p>\n

\u91cd\u8981\u6982\u5ff5: ECMAScript<\/p>\n

\u524d\u7f6e\u77e5\u8bc6<\/p>\n

\u7b2c\u4e00\u4e2a\u7a0b\u5e8f<\/p>\n

JavaScript\u7684\u4e66\u5199\u5f62\u5f0f<\/p>\n

\u884c\u5185\u5f0f<\/p>\n

\u5185\u5d4c\u5f0f<\/p>\n

\u5916\u90e8\u5f0f<\/p>\n

\u6ce8\u91ca<\/p>\n

\u8f93\u5165\u8f93\u51fa<\/p>\n

\u8f93\u5165：prompt<\/p>\n

\u8f93\u51fa：alert<\/p>\n

\u8f93\u51fa：console.log<\/p>\n

\u91cd\u8981\u6982\u5ff5：\u65e5\u5fd7<\/p>\n

\u91cd\u8981\u6982\u5ff5：<\/p>\n

\u8bed\u6cd5\u6982\u89c8<\/p>\n

\u53d8\u91cf\u7684\u4f7f\u7528<\/p>\n

\u57fa\u672c\u7528\u6cd5<\/p>\n

\u4f7f\u7528\u53d8\u91cf<\/p>\n

\u4ee3\u7801\u793a\u4f8b：\u5f39\u6846\u63d0\u793a\u7528\u6237\u8f93\u5165\u4fe1\u606f, \u518d\u5f39\u6846\u663e\u793a<\/p>\n

\u7406\u89e3\u52a8\u6001\u7c7b\u578b<\/p>\n

1) JS \u7684\u53d8\u91cf\u7c7b\u578b\u662f\u7a0b\u5e8f\u8fd0\u884c\u8fc7\u7a0b\u4e2d\u624d\u786e\u5b9a\u7684(\u8fd0\u884c\u5230 = \u8bed\u53e5\u624d\u4f1a\u786e\u5b9a\u7c7b\u578b)<\/p>\n

2) \u968f\u7740\u7a0b\u5e8f\u8fd0\u884c, \u53d8\u91cf\u7684\u7c7b\u578b\u53ef\u80fd\u4f1a\u53d1\u751f\u6539\u53d8.<\/p>\n

\u57fa\u672c\u6570\u636e\u7c7b\u578b<\/p>\n

number\u6570\u5b57\u7c7b\u578b<\/p>\n

\u6570\u5b57\u8fdb\u5236\u8868\u793a<\/p>\n

\u7279\u6b8a\u7684\u6570\u5b57\u503c<\/p>\n

string\u5b57\u7b26\u4e32\u7c7b\u578b<\/p>\n

\u57fa\u672c\u89c4\u5219<\/p>\n

\u8f6c\u4e49\u5b57\u7b26<\/p>\n

\u6c42\u957f\u5ea6<\/p>\n

\u5b57\u7b26\u4e32\u62fc\u63a5<\/p>\n

boolean\u5e03\u5c14\u7c7b\u578b<\/p>\n

undefined\u672a\u5b9a\u4e49\u6570\u636e\u7c7b\u578b<\/p>\n

null\u7a7a\u503c\u7c7b\u578b<\/p>\n

\u8fd0\u7b97\u7b26<\/p>\n

\u7b97\u672f\u8fd0\u7b97\u7b26<\/p>\n

\u8d4b\u503c\u8fd0\u7b97\u7b26&\u590d\u5408\u8d4b\u503c\u8fd0\u7b97\u7b26<\/p>\n

\u81ea\u589e\u81ea\u51cf\u8fd0\u7b97\u7b26<\/p>\n

\u6bd4\u8f83\u8fd0\u7b97\u7b26<\/p>\n

\u903b\u8f91\u8fd0\u7b97\u7b26<\/p>\n

\u4f4d\u8fd0\u7b97<\/p>\n

\u79fb\u4f4d\u8fd0\u7b97<\/p>\n

\u6761\u4ef6\u8bed\u53e5<\/p>\n

if\u8bed\u53e5<\/p>\n

\u57fa\u672c\u8bed\u6cd5\u683c\u5f0f<\/p>\n

\u7ec3\u4e60\u6848\u4f8b<\/p>\n

\u4ee3\u7801\u793a\u4f8b1：\u5224\u5b9a\u4e00\u4e2a\u6570\u5b57\u662f\u5947\u6570\u8fd8\u662f\u5076\u6570<\/p>\n

\u4ee3\u7801\u793a\u4f8b2：\u5224\u5b9a\u4e00\u4e2a\u6570\u5b57\u662f\u6b63\u6570\u8fd8\u662f\u8d1f\u6570<\/p>\n

\u4ee3\u7801\u793a\u4f8b3：\u5224\u5b9a\u67d0\u4e00\u5e74\u4efd\u662f\u5426\u662f\u95f0\u5e74<\/p>\n

\u4e09\u5143\u8868\u8fbe\u5f0f<\/p>\n

switch<\/p>\n

\u8c03\u8bd5\u6280\u5de7<\/p>\n

\u5faa\u73af\u8bed\u53e5<\/p>\n

while\u5faa\u73af<\/p>\n

\u4ee3\u7801\u793a\u4f8b1：\u6253\u53701-10<\/p>\n

\u4ee3\u7801\u793a\u4f8b2：\u8ba1\u7b975\u7684\u9636\u4e58<\/p>\n

continue<\/p>\n

\u4ee3\u7801\u793a\u4f8b：\u627e\u5230100-200\u4e2d\u6240\u67093\u7684\u500d\u6570<\/p>\n

break<\/p>\n

\u4ee3\u7801\u793a\u4f8b：\u627e\u5230100-200\u4e2d\u7b2c\u4e00\u4e2a3\u7684\u500d\u6570<\/p>\n

for\u5faa\u73af<\/p>\n

\u4ee3\u7801\u793a\u4f8b1：\u6253\u53701-10\u7684\u6570\u5b57<\/p>\n

\u4ee3\u7801\u793a\u4f8b2：\u8ba1\u7b975\u7684\u9636\u4e58<\/p>\n

\n

\u521d\u8bc6JavaScript<\/h2>\n

JavaScript\u662f\u4ec0\u4e48<\/h3>\n

JavaScript（\u7b80\u79f0 JS）<\/p>\n

\u662f\u4e16\u754c\u4e0a\u6700\u6d41\u884c\u7684\u7f16\u7a0b\u8bed\u8a00\u4e4b\u4e00<\/p>\n

\u662f\u4e00\u4e2a\u811a\u672c\u8bed\u8a00，\u901a\u8fc7\u89e3\u91ca\u5668\u8fd0\u884c<\/p>\n

\u4e3b\u8981\u5728\u5ba2\u6237\u7aef（\u6d4f\u89c8\u5668）\u4e0a\u8fd0\u884c，\u73b0\u5728\u4e5f\u53ef\u4ee5\u57fa\u4e8e node.js \u5728\u670d\u52a1\u5668\u7aef\u8fd0\u884c<\/p>\n

JavaScript \u6700\u521d\u53ea\u662f\u4e3a\u4e86\u5b8c\u6210\u7b80\u5355\u7684\u8868\u5355\u9a8c\u8bc1（\u9a8c\u8bc1\u6570\u636e\u5408\u6cd5\u6027），\u7ed3\u679c\u540e\u6765\u4e0d\u5c0f\u5fc3\u5c31\u706b\u4e86<\/p>\n

\u5f53\u524d JavaScript \u5df2\u7ecf\u6210\u4e3a\u4e86\u4e00\u4e2a\u901a\u7528\u7684\u7f16\u7a0b\u8bed\u8a00<\/p>\n

JavaScript \u7684\u80fd\u505a\u7684\u4e8b\u60c5:<\/p>\n

\u7f51\u9875\u5f00\u53d1(\u66f4\u590d\u6742\u7684\u7279\u6548\u548c\u7528\u6237\u4ea4\u4e92)<\/p>\n

\u7f51\u9875\u6e38\u620f\u5f00\u53d1<\/p>\n

\u670d\u52a1\u5668\u5f00\u53d1(node.js)<\/p>\n

\u684c\u9762\u7a0b\u5e8f\u5f00\u53d1(Electron, VSCode \u5c31\u662f\u8fd9\u4e48\u6765\u7684)<\/p>\n

\u624b\u673a app \u5f00\u53d1<\/p>\n

\u53d1\u5c55\u5386\u53f2<\/h3>\n

JavaScript \u4e4b\u7236 \u5e03\u5170\u767b * \u827e\u5947 (Brendan Eich)<\/p>\n

\u66fe\u7ecf\u7684\u5e03\u5170\u767b<\/p>\n

\u00a0 <\/p>\n

\"\"<\/p>\n

\u53d1\u660e JavaScript \u4e4b\u540e\u7684\u5e03\u5170\u767b <\/p>\n

\"\"<\/p>\n

1995 \u5e74, \u7528 10 \u5929\u65f6\u95f4\u5b8c\u6210 JS \u7684\u8bbe\u8ba1 (\u7531\u4e8e\u8bbe\u8ba1\u65f6\u95f4\u592a\u77ed，\u8bed\u8a00\u7684\u4e00\u4e9b\u7ec6\u8282\u8003\u8651\u5f97\u4e0d\u591f\u4e25\u8c28，\u5bfc\u81f4\u540e\u6765\u5f88\u957f\u4e00\u6bb5\u65f6\u95f4，Javascript \u5199\u51fa\u6765\u7684\u7a0b\u5e8f\u6df7\u4e71\u4e0d\u582a)<\/p>\n

\u6700\u521d\u5728\u7f51\u666f\u516c\u53f8, \u547d\u540d\u4e3a LiveScript,<\/p>\n

\u4e00\u822c\u8ba4\u4e3a，\u5f53\u65f6 Netscape \u4e4b\u6240\u4ee5\u5c06 LiveScript \u547d\u540d\u4e3a JavaScript，\u662f\u56e0\u4e3a Java \u662f\u5f53\u65f6\u6700\u6d41\u884c\u7684\u7f16\u7a0b\u8bed\u8a00，\u5e26\u6709 "Java" \u7684\u540d\u5b57\u6709\u52a9\u4e8e\u8fd9\u95e8\u65b0\u751f\u8bed\u8a00\u7684\u4f20\u64ad\u3002<\/p>\n

\u5176\u5b9e Java \u548c JavaScript \u4e4b\u95f4\u7684\u8bed\u6cd5\u98ce\u683c\u76f8\u53bb\u751a\u8fdc.<\/p>\n

\"\"<\/p>\n

JavaScript \u53d1\u5c55\u5386\u53f2\u53ef\u4ee5\u53c2\u8003\u962e\u4e00\u5cf0\u5927\u795e\u7684\u535a\u5ba2<\/p>\n

JavaScript\u548cHTML\u548cCSS\u4e4b\u95f4\u7684\u5173\u7cfb<\/h3>\n

\"\"<\/p>\n

HTML: \u7f51\u9875\u7684\u7ed3\u6784(\u9aa8)<\/p>\n

CSS: \u7f51\u9875\u7684\u8868\u73b0(\u76ae)<\/p>\n

JavaScript: \u7f51\u9875\u7684\u884c\u4e3a(\u9b42)<\/p>\n

\"\"<\/p>\n

JavaScript\u8fd0\u884c\u8fc7\u7a0b<\/h3>\n

\u7f16\u5199\u7684\u4ee3\u7801\u662f\u4fdd\u5b58\u5728\u6587\u4ef6\u4e2d\u7684, \u4e5f\u5c31\u662f\u5b58\u50a8\u5728\u786c\u76d8(\u5916\u5b58\u4e0a).<\/p>\n

\u53cc\u51fb .html \u6587\u4ef6\u6d4f\u89c8\u5668(\u5e94\u7528\u7a0b\u5e8f)\u5c31\u4f1a\u8bfb\u53d6\u6587\u4ef6, \u628a\u6587\u4ef6\u5185\u5bb9\u52a0\u8f7d\u5230\u5185\u5b58\u4e2d(\u6570\u636e\u6d41\u5411: \u786c\u76d8 => \u5185\u5b58)<\/p>\n

\u6d4f\u89c8\u5668\u4f1a\u89e3\u6790\u7528\u6237\u7f16\u5199\u7684\u4ee3\u7801, \u628a\u4ee3\u7801\u7ffb\u8bd1\u6210\u4e8c\u8fdb\u5236\u7684, \u80fd\u8ba9\u8ba1\u7b97\u673a\u8bc6\u522b\u7684\u6307\u4ee4(\u89e3\u91ca\u5668\u7684\u5de5\u4f5c)\u5f97\u5230\u7684\u4e8c\u8fdb\u5236\u6307\u4ee4\u4f1a\u88ab CPU \u52a0\u8f7d\u5e76\u6267\u884c(\u6570\u636e\u6d41\u5411: \u5185\u5b58 => CPU)<\/p>\n

\"\"<\/p>\n

\u6d4f\u89c8\u5668\u5206\u6210\u6e32\u67d3\u5f15\u64ce + JS \u5f15\u64ce.<\/p>\n

\u6e32\u67d3\u5f15\u64ce: \u89e3\u6790 html + CSS, \u4fd7\u79f0 "\u5185\u6838"<\/p>\n

JS \u5f15\u64ce: \u4e5f\u5c31\u662f JS \u89e3\u91ca\u5668. \u5178\u578b\u7684\u5c31\u662f Chrome \u4e2d\u5185\u7f6e\u7684 V8<\/p>\n

JS \u5f15\u64ce\u9010\u884c\u8bfb\u53d6 JS \u4ee3\u7801\u5185\u5bb9, \u7136\u540e\u89e3\u6790\u6210\u4e8c\u8fdb\u5236\u6307\u4ee4, \u518d\u6267\u884c<\/p>\n

JavaScript\u7684\u7ec4\u6210<\/h3>\n

ECMAScript(\u7b80\u79f0 ES): JavaScript \u8bed\u6cd5<\/p>\n

DOM: \u9875\u9762\u6587\u6863\u5bf9\u8c61\u6a21\u578b, \u5bf9\u9875\u9762\u4e2d\u7684\u5143\u7d20\u8fdb\u884c\u64cd\u4f5c<\/p>\n

BOM: \u6d4f\u89c8\u5668\u5bf9\u8c61\u6a21\u578b, \u5bf9\u6d4f\u89c8\u5668\u7a97\u53e3\u8fdb\u884c\u64cd\u4f5c<\/p>\n

\u5149\u6709 JS \u8bed\u6cd5, \u53ea\u80fd\u5199\u4e00\u4e9b\u57fa\u7840\u7684\u903b\u8f91\u6d41\u7a0b.<\/p>\n

\u4f46\u662f\u8981\u60f3\u5b8c\u6210\u66f4\u590d\u6742\u7684\u4efb\u52a1, \u5b8c\u6210\u548c\u6d4f\u89c8\u5668\u4ee5\u53ca\u9875\u9762\u7684\u4ea4\u4e92, \u90a3\u4e48\u5c31\u9700\u8981 DOM API \u548c BOM API.<\/p>\n

\u8fd9\u4e3b\u8981\u6307\u5728\u6d4f\u89c8\u5668\u7aef\u8fd0\u884c\u7684 JS. \u5982\u679c\u662f\u8fd0\u884c\u5728\u670d\u52a1\u7aef\u7684 JS , \u5219\u9700\u8981\u4f7f\u7528 node.js \u7684 API,<\/p>\n

\u5c31\u4e0d\u592a\u9700\u8981\u5173\u6ce8 DOM \u548c BOM<\/p>\n

\u91cd\u8981\u6982\u5ff5: ECMAScript<\/h4>\n

\u8fd9\u662f\u4e00\u5957 "\u6807\u51c6", \u65e0\u8bba\u662f\u5565\u6837\u7684 JS \u5f15\u64ce\u90fd\u8981\u9075\u5b88\u8fd9\u4e2a\u6807\u51c6\u6765\u5b9e\u73b0.<\/p>\n

\u5565\u53eb\u6807\u51c6? \u8f66\u540c\u8f68, \u4e66\u540c\u6587. \u79e6\u59cb\u7687\u6700\u5927\u7684\u8d21\u732e\u4e4b\u4e00, \u5c31\u662f\u5236\u5b9a\u4e86\u4e00\u5957\u6807\u51c6.<\/p>\n

\u4e09\u6d41\u516c\u53f8\u505a\u4ea7\u54c1, \u4e00\u6d41\u516c\u53f8\u505a\u6807\u51c6<\/p>\n

\u524d\u7f6e\u77e5\u8bc6<\/h2>\n

\u7b2c\u4e00\u4e2a\u7a0b\u5e8f<\/h3>\n

\u6253\u5f00\u6d4f\u89c8\u5668，\u6309\u4e0b F12\u6253\u5f00\u5f00\u53d1\u8005\u6a21\u5f0f\u540e\u5728\u63a7\u5236\u53f0（Console）\u76f4\u63a5\u8f93\u5165\u4e00\u4e2aJavaScript\u8bed\u53e5，\u5c31\u80fd\u660e\u663e\u89c1\u5230\u56de\u5e94\u6548\u679c👇<\/p>\n

\"\"<\/p>\n

<script>
\n \u00a0 \u00a0alert("\u4f60\u597d!");
\n<\/script> <\/p>\n

JavaScript \u4ee3\u7801\u53ef\u4ee5\u5d4c\u5165\u5230 HTML \u7684 script \u6807\u7b7e\u4e2d.<\/p>\n

JavaScript\u7684\u4e66\u5199\u5f62\u5f0f<\/h3>\n

\u884c\u5185\u5f0f<\/h4>\n

\u76f4\u63a5\u5d4c\u5165\u5230 html \u5143\u7d20\u5185\u90e8<\/p>\n

<input type="button" value="\u70b9\u6211\u4e00\u4e0b" onclick="alert('haha')"> <\/p>\n

\u6ce8\u610f, JS \u4e2d\u5b57\u7b26\u4e32\u5e38\u91cf\u53ef\u4ee5\u4f7f\u7528\u5355\u5f15\u53f7\u8868\u793a, \u4e5f\u53ef\u4ee5 \u4f7f\u7528\u53cc\u5f15\u53f7\u8868\u793a.<\/p>\n

HTML \u4e2d\u63a8\u8350\u4f7f\u7528\u53cc\u5f15\u53f7, JS \u4e2d\u63a8\u8350\u4f7f\u7528\u5355\u5f15\u53f7<\/p>\n

\u4ee3\u7801\u5c55\u793a👇<\/p>\n

<!DOCTYPE html>
\n<html lang="en">
\n<head>
\n <meta charset="UTF-8">
\n <meta name="viewport" content="width=device-width, initial-scale=1.0">
\n <title>Document<\/title>
\n<\/head>
\n<body>
\n <input type="button" value="\u70b9\u6211\u4e00\u4e0b" onclick="alert('haha')">
\n<\/body>
\n<\/html> <\/p>\n

\u6548\u679c\u5c55\u793a👇<\/p>\n

\"\"<\/p>\n

\u6ce8\u610f：\u5728 JavaScript \u4e2d\u53ef\u4ee5 \u5355\u5f15\u53f7\u548c\u53cc\u5f15\u53f7\u53ef\u4ee5\u5207\u6362\u4f7f\u7528，\u5728\u4e0a\u8ff0\u4ee3\u7801\u4e2d\u5c06\u5355\u5f15\u53f7\u548c\u53cc\u5f15\u53f7\u4e92\u6362\u4f4d\u7f6e\u540e，\u4ee3\u7801\u6548\u679c\u662f\u4e00\u6837\u7684<\/p>\n

\u5185\u5d4c\u5f0f<\/h4>\n

\u5199\u5230 script \u6807\u7b7e\u4e2d<\/p>\n

<script>
\n \u00a0 \u00a0alert("haha");
\n<\/script> <\/p>\n

\u5916\u90e8\u5f0f<\/h4>\n

\u5199\u5230\u5355\u72ec\u7684 .js \u6587\u4ef6\u4e2d<\/p>\n

<script src="hello.js"><\/script>
\n alert("hehe"); <\/p>\n

\u6ce8\u610f, \u8fd9\u79cd\u60c5\u51b5\u4e0b script \u6807\u7b7e\u4e2d\u95f4\u4e0d\u80fd\u5199\u4ee3\u7801. \u5fc5\u987b\u7a7a\u7740(\u5199\u4e86\u4ee3\u7801\u4e5f\u4e0d\u4f1a\u6267\u884c).<\/p>\n

\u9002\u5408\u4ee3\u7801\u591a\u7684\u60c5\u51b5<\/p>\n

\u4ee3\u7801\u5c55\u793a👇<\/p>\n

<!DOCTYPE html>
\n<html lang="en">
\n<head>
\n <meta charset="UTF-8">
\n <meta name="viewport" content="width=device-width, initial-scale=1.0">
\n <title>Document<\/title>
\n<\/head>
\n<body>
\n <script src=".\/demo02.js"><\/script>
\n<\/body>
\n<\/html>
\n alert("\u6211\u5728\u5b66\u4e60JavaScript"); <\/p>\n

\u6548\u679c\u5c55\u793a👇<\/p>\n

\"\"<\/p>\n

\u6ce8\u91ca<\/h4>\n

\u5355\u884c\u6ce8\u91ca \/\/ [\u5efa\u8bae\u4f7f\u7528]<\/p>\n

\u591a\u884c\u6ce8\u91ca \/* *\/<\/p>\n

\/\/ \u6211\u662f\u5355\u884c\u6ce8\u91ca
\n\/*
\n \u00a0 \u6211\u662f\u591a\u884c\u6ce8\u91ca
\n \u00a0 \u6211\u662f\u591a\u884c\u6ce8\u91ca
\n \u00a0 \u6211\u662f\u591a\u884c\u6ce8\u91ca
\n*\/ <\/p>\n

\u4f7f\u7528 ctrl + \/ \u5207\u6362\u6ce8\u91ca.<\/p>\n

\u591a\u884c\u6ce8\u91ca\u4e0d\u80fd\u5d4c\u5957. \u5f62\u5982\u8fd9\u79cd\u4ee3\u7801\u5c31\u4f1a\u62a5\u9519<\/p>\n

\/*
\n\/*
\n \u00a0 \u6211\u662f\u591a\u884c\u6ce8\u91ca
\n \u00a0 \u6211\u662f\u591a\u884c\u6ce8\u91ca
\n \u00a0 \u6211\u662f\u591a\u884c\u6ce8\u91ca
\n*\/
\n*\/ <\/p>\n

\u8f93\u5165\u8f93\u51fa<\/h3>\n

\u8f93\u5165：prompt<\/h4>\n

\u5f39\u51fa\u4e00\u4e2a\u8f93\u5165\u6846<\/p>\n

\/\/ \u5f39\u51fa\u4e00\u4e2a\u8f93\u5165\u6846
\nprompt("\u8bf7\u8f93\u5165\u60a8\u7684\u59d3\u540d:"); <\/p>\n

\u8f93\u51fa：alert<\/h4>\n

\u5f39\u51fa\u4e00\u4e2a\u8b66\u793a\u5bf9\u8bdd\u6846, \u8f93\u51fa\u7ed3\u679c<\/p>\n

\/\/ \u5f39\u51fa\u4e00\u4e2a\u8f93\u51fa\u6846
\nalert("hello"); <\/p>\n

\u8f93\u51fa：console.log<\/h4>\n

\u5728\u63a7\u5236\u53f0\u6253\u5370\u4e00\u4e2a\u65e5\u5fd7(\u4f9b\u7a0b\u5e8f\u5458\u770b)<\/p>\n

\/\/ \u5411\u63a7\u5236\u53f0\u8f93\u51fa\u65e5\u5fd7
\nconsole.log("\u8fd9\u662f\u4e00\u6761\u65e5\u5fd7"); <\/p>\n

\u6ce8\u610f: \u5728 VSCode \u4e2d\u76f4\u63a5\u8f93\u5165 "log" \u518d\u6309 tab \u952e, \u5c31\u53ef\u4ee5\u5feb\u901f\u8f93\u5165 console.log<\/p>\n

\u9700\u8981\u6253\u5f00\u6d4f\u89c8\u5668\u7684\u5f00\u53d1\u8005\u5de5\u5177(F12) => Console \u6807\u7b7e\u9875 \u624d\u80fd\u770b\u5230\u7ed3\u679c<\/p>\n

\"\"<\/p>\n

\u8fd9\u6837\u7684\u8f93\u51fa\u4e00\u822c\u4e0d\u662f\u7ed9\u666e\u901a\u7528\u6237\u770b\u7684, \u800c\u662f\u7a0b\u5e8f\u5458\u6765\u770b\u7684.<\/p>\n

\u91cd\u8981\u6982\u5ff5：\u65e5\u5fd7<\/h4>\n

\u65e5\u5fd7\u662f\u7a0b\u5e8f\u5458\u8c03\u8bd5\u7a0b\u5e8f\u7684\u91cd\u8981\u624b\u6bb5<\/p>\n

\u53bb\u533b\u9662\u770b\u75c5, \u533b\u751f\u4f1a\u8ba9\u60a3\u8005\u505a\u5404\u79cd\u68c0\u67e5, \u8840\u5e38\u89c4, \u5c3f\u5e38\u89c4, B\u8d85, CT\u7b49… \u6b64\u65f6\u5f97\u5230\u4e00\u5806\u68c0\u6d4b\u7ed3\u679c. \u8fd9\u4e9b\u7ed3\u679c\u666e\u901a\u4eba\u770b\u4e0d\u61c2, \u4f46\u662f\u533b\u751f\u80fd\u770b\u61c2, \u5e76\u4e14\u533b\u751f\u8981\u901a\u8fc7\u8fd9\u4e9b\u4fe1\u606f\u6765\u8bca\u65ad\u75c5\u60c5.<\/p>\n

\u8fd9\u4e9b\u68c0\u6d4b\u7ed3\u679c\u5c31\u662f\u533b\u751f\u7684 "\u65e5\u5fd7"<\/p>\n

PS: \u76f8\u6bd4\u4e8e\u533b\u751f\u6765\u8bf4, \u7a0b\u5e8f\u733f\u591a\u4e00\u4e2a\u7ec8\u6781\u5927\u62db, "\u91cd\u542f\u4e0b\u8bd5\u8bd5".<\/p>\n

\u91cd\u8981\u6982\u5ff5：<\/h4>\n

console \u662f\u4e00\u4e2a js \u4e2d\u7684 "\u5bf9\u8c61"<\/p>\n

. \u8868\u793a\u53d6\u5bf9\u8c61\u4e2d\u7684\u67d0\u4e2a\u5c5e\u6027\u6216\u8005\u65b9\u6cd5. \u53ef\u4ee5\u76f4\u89c2\u7406\u89e3\u6210 "\u7684"<\/p>\n

console.log \u5c31\u53ef\u4ee5\u7406\u89e3\u6210: \u4f7f\u7528 "\u63a7\u5236\u53f0" \u5bf9\u8c61 "\u7684" log \u65b9\u6cd5<\/p>\n

\u8bed\u6cd5\u6982\u89c8<\/h2>\n

JavaScript \u867d\u7136\u4e00\u4e9b\u8bbe\u8ba1\u7406\u5ff5\u548c Java \u76f8\u53bb\u751a\u8fdc, \u4f46\u662f\u5728\u57fa\u7840\u8bed\u6cd5\u5c42\u9762\u4e0a\u8fd8\u662f\u6709\u4e00\u4e9b\u76f8\u4f3c\u4e4b\u5904\u7684.<\/p>\n

\u6709\u4e86 Java \u7684\u57fa\u7840\u5f88\u5bb9\u6613\u7406\u89e3 JavaScript \u7684\u4e00\u4e9b\u57fa\u672c\u8bed\u6cd5<\/p>\n

\u53d8\u91cf\u7684\u4f7f\u7528<\/h3>\n

\u57fa\u672c\u7528\u6cd5<\/h4>\n

\u521b\u5efa\u53d8\u91cf(\u53d8\u91cf\u5b9a\u4e49\/\u53d8\u91cf\u58f0\u660e\/\u53d8\u91cf\u521d\u59cb\u5316)<\/p>\n

var name = 'zhangsan';
\nvar age = 20; <\/p>\n

\u4ee3\u7801\u5c55\u793a👇<\/p>\n

<!DOCTYPE html>
\n<html lang="en">
\n<head>
\n <meta charset="UTF-8">
\n <meta name="viewport" content="width=device-width, initial-scale=1.0">
\n <title>Document<\/title>
\n<\/head>
\n<body>
\n <!– <input type="button" value="\u70b9\u6211\u4e00\u4e0b" onclick="alert('haha')"> –>
\n<\/body>
\n<script>
\n var name="CoderYanger";
\n console.log(name)
\n<\/script>
\n<\/html> <\/p>\n

\u6253\u5370\u6548\u679c\u5c55\u793a👇<\/p>\n

\"\"<\/p>\n

var \u662f JS \u4e2d\u7684\u5173\u952e\u5b57, \u8868\u793a\u8fd9\u662f\u4e00\u4e2a\u53d8\u91cf.<\/p>\n

= \u5728 JS \u4e2d\u8868\u793a "\u8d4b\u503c", \u76f8\u5f53\u4e8e\u628a\u6570\u636e\u653e\u5230\u5185\u5b58\u7684\u76d2\u5b50\u4e2d. = \u4e24\u4fa7\u5efa\u8bae\u6709\u4e00\u4e2a\u7a7a\u683c<\/p>\n

\u6bcf\u4e2a\u8bed\u53e5\u6700\u540e\u5e26\u6709\u4e00\u4e2a ; \u7ed3\u5c3e. JS \u4e2d\u53ef\u4ee5\u7701\u7565 ; \u4f46\u662f\u5efa\u8bae\u8fd8\u662f\u52a0\u4e0a.<\/p>\n

\u6ce8\u610f, \u6b64\u5904\u7684 ; \u4e3a\u82f1\u6587\u5206\u53f7. JS \u4e2d\u6240\u6709\u7684\u6807\u70b9\u90fd\u662f\u82f1\u6587\u6807\u70b9.<\/p>\n

\u521d\u59cb\u5316\u7684\u503c\u5982\u679c\u662f\u5b57\u7b26\u4e32, \u90a3\u4e48\u5c31\u8981\u4f7f\u7528\u5355\u5f15\u53f7\u6216\u8005\u53cc\u5f15\u53f7\u5f15\u8d77\u6765.<\/p>\n

\u521d\u59cb\u5316\u7684\u503c\u5982\u679c\u662f\u6570\u5b57, \u90a3\u4e48\u76f4\u63a5\u8d4b\u503c\u5373\u53ef<\/p>\n

\u8fd8\u6709\u53e6\u5916\u4e00\u79cd\u5b9a\u4e49\u65b9\u5f0f：\u4f7f\u7528 let，\u4ee3\u7801\u5c55\u793a👇<\/p>\n

<!DOCTYPE html>
\n<html lang="en">
\n<head>
\n <meta charset="UTF-8">
\n <meta name="viewport" content="width=device-width, initial-scale=1.0">
\n <title>Document<\/title>
\n<\/head>
\n<body>
\n <!– <input type="button" value="\u70b9\u6211\u4e00\u4e0b" onclick="alert('haha')"> –>
\n<\/body>
\n<script>
\n var name="CoderYanger";
\n console.log(name)
\n let age=30;
\n console.log(age)
\n<\/script>
\n<\/html> <\/p>\n

\u6548\u679c\u5c55\u793a👇<\/p>\n

\"\"<\/p>\n

\u4e3a\u4ec0\u4e48\u66f4\u52a0\u63a8\u8350\u4f7f\u7528 let \u4ee3\u66ff var \u5462？？<\/p>\n

\u56e0\u4e3a let \u6bd4 var \u51fa\u73b0\u7684\u665a，\u610f\u5473\u7740\u907f\u514d\u4e86 var \u8fd9\u5757\u5b9a\u4e49\u53d8\u91cf\u7684\u65f6\u5019\u7684\u4e00\u4e9b\u7f3a\u9677<\/p>\n

\u5982\u679c\u4f7f\u7528 let \u5b9a\u4e49\u53d8\u91cf，\u6b64\u65f6\u751f\u547d\u5468\u671f\u3001\u4f5c\u7528\u57df，\u57fa\u672c\u548c Java \u662f\u7c7b\u4f3c\u7684<\/p>\n

\u800c\u4e14 JS \u5b9a\u4e49\u4e00\u4e2a\u53d8\u91cf\u7684\u65f6\u5019，\u4e0d\u9700\u8981\u5bf9\u8fd9\u4e2a\u53d8\u91cf\u6307\u5b9a\u7c7b\u578b~~<\/p>\n

\u4f60\u7ed9\u8d4b\u503c\u6210\u5b57\u7b26\u4e32，\u5c31\u662f\u5b57\u7b26\u4e32，\u4f60\u7ed9\u8d4b\u503c\u6570\u5b57，\u90a3\u5c31\u662f\u6570\u5b57<\/p>\n

\u540c\u65f6，\u5728 JS \u91cc\u9762\u5bf9\u4e8e\u6570\u5b57\u53ea\u6709\u4e00\u79cd\u7c7b\u578b：\u6570\u503c\u7c7b\u578b（\u53ef\u4ee5\u662f\u5c0f\u6570，\u4e5f\u53ef\u4ee5\u662f\u6574\u6570）<\/p>\n

\u4f7f\u7528\u53d8\u91cf<\/h5>\n

console.log(age); \/\/ \u8bfb\u53d6\u53d8\u91cf\u5185\u5bb9
\nage = 30; \u00a0 \u00a0 \u00a0 \u00a0 \/\/ \u4fee\u6539\u53d8\u91cf\u5185\u5bb9 <\/p>\n

\u4e3a\u5565\u52a8\u6f2b\u4e2d\u7684\u89d2\u8272\u90fd\u662f\u8981\u5148\u558a\u51fa\u6280\u80fd\u540d\u5b57\u518d\u771f\u6b63\u91ca\u653e\u6280\u80fd?<\/p>\n

\u5c31\u662f\u56e0\u4e3a\u53d8\u91cf\u8981\u5148\u58f0\u660e\u624d\u80fd\u4f7f\u7528<\/p>\n

\u4ee3\u7801\u793a\u4f8b：\u5f39\u6846\u63d0\u793a\u7528\u6237\u8f93\u5165\u4fe1\u606f, \u518d\u5f39\u6846\u663e\u793a<\/h5>\n

var name = prompt("\u8bf7\u8f93\u5165\u59d3\u540d:");
\nvar age = prompt("\u8bf7\u8f93\u5165\u5e74\u9f84:");
\nvar score = prompt("\u8bf7\u8f93\u5165\u5206\u6570");
\nalert("\u60a8\u7684\u59d3\u540d\u662f: " + name);
\nalert("\u60a8\u7684\u5e74\u9f84\u662f: " + age);
\nalert("\u60a8\u7684\u5206\u6570\u662f: " + score); <\/p>\n

\u4e5f\u53ef\u4ee5\u628a\u4e09\u4e2a\u8f93\u51fa\u5185\u5bb9\u5408\u5e76\u6210\u4e00\u6b21\u5f39\u6846<\/p>\n

var name = prompt("\u8bf7\u8f93\u5165\u59d3\u540d:");
\nvar age = prompt("\u8bf7\u8f93\u5165\u5e74\u9f84:");
\nvar score = prompt("\u8bf7\u8f93\u5165\u5206\u6570");
\nalert("\u60a8\u7684\u59d3\u540d\u662f: " + name + "\\\\n" + "\u60a8\u7684\u5e74\u9f84\u662f: " + age + "\\\\n" + "\u60a8\u7684\u5206\u6570\u662f: " +
\nscore + "\\\\n"); <\/p>\n

+ \u8868\u793a\u5b57\u7b26\u4e32\u62fc\u63a5, \u4e5f\u5c31\u662f\u628a\u4e24\u4e2a\u5b57\u7b26\u4e32\u9996\u5c3e\u76f8\u63a5\u53d8\u6210\u4e00\u4e2a\u5b57\u7b26\u4e32.<\/p>\n

\\\\n \u8868\u793a\u6362\u884c<\/p>\n

JavaScript \u4e2d\u8fd8\u652f\u6301\u4f7f\u7528 let \u5b9a\u4e49\u53d8\u91cf. \u7528\u6cd5\u548c var \u57fa\u672c\u7c7b\u4f3c. \u7528\u6cd5\u4e0a\u7684\u5dee\u5f02\u6b64\u5904\u6682\u65f6\u4e0d\u8ba8\u8bba.<\/p>\n

\u7406\u89e3\u52a8\u6001\u7c7b\u578b<\/h4>\n

\u7b54\u7591<\/span><\/p>\n

Q1：\u4ec0\u4e48\u662f\u5f3a\u7c7b\u578b\u53d8\u91cf？\u4ec0\u4e48\u662f\u5f31\u7c7b\u578b\u53d8\u91cf？<\/span><\/p>\n

\u4ee3\u7801\u5c55\u793a👇<\/p>\n

<!DOCTYPE html>
\n<html lang="en">
\n<head>
\n <meta charset="UTF-8">
\n <meta name="viewport" content="width=device-width, initial-scale=1.0">
\n <title>Document<\/title>
\n<\/head>
\n<body>
\n <script>
\n a = 1
\n b = 'b'
\n b = a
\n console.log(b)
\n <\/script>
\n<\/body>
\n<\/html> <\/p>\n

\u6548\u679c\u5c55\u793a👇\"\"<\/p>\n

\u6211\u4eec\u53d1\u73b0 b = 1，\u4e14\u4ee3\u7801\u4e5f\u6ca1\u6709\u62a5\u9519，\u8bc1\u660e JavaScript \u5c5e\u4e8e\u5f31\u7c7b\u578b\u8bed\u8a00，\u5b83\u6240\u5b9a\u4e49\u7684\u53d8\u91cf\u4e5f\u5c31\u5c5e\u4e8e\u5f31\u7c7b\u578b\u53d8\u91cf~~<\/p>\n

Q2：\u4ec0\u4e48\u662f\u52a8\u6001\u7c7b\u578b\u53d8\u91cf？\u4ec0\u4e48\u662f\u9759\u6001\u7c7b\u578b\u53d8\u91cf？<\/span><\/p>\n

\u52a8\u6001\u7c7b\u578b\u610f\u5473\u7740\u4ee3\u7801\u5728\u6267\u884c\u8fc7\u7a0b\u4e2d，\u53d8\u91cf\u7c7b\u578b\u53ef\u4ee5\u968f\u65f6\u53d1\u751f\u53d8\u5316<\/p>\n

\u9759\u6001\u7c7b\u578b\u610f\u5473\u7740\u53d8\u91cf\u5b9a\u4e49\u7684\u65f6\u5019\u662f\u4ec0\u4e48\u7c7b\u578b，\u5728\u8fd0\u884c\u8fc7\u7a0b\u4e2d\u5c31\u662f\u4ec0\u4e48\u7c7b\u578b<\/p>\n

\u6211\u4eec\u53ef\u4ee5\u5c06\u4e0a\u8ff0\u4ee3\u7801\u7a0d\u4f5c\u4fee\u6539，\u89c2\u5bdf a \u7684\u7c7b\u578b\u662f\u5426\u6539\u53d8，\u4ee3\u7801\u5c55\u793a👇<\/p>\n

<!DOCTYPE html>
\n<html lang="en">
\n<head>
\n <meta charset="UTF-8">
\n <meta name="viewport" content="width=device-width, initial-scale=1.0">
\n <title>Document<\/title>
\n<\/head>
\n<body>
\n <script>
\n a = 1
\n console.log(typeof(a))
\n b = 'b'
\n a = b
\n console.log(typeof(a))
\n <\/script>
\n<\/body>
\n<\/html> <\/p>\n

\u6548\u679c\u5c55\u793a👇<\/p>\n

\"\"<\/p>\n

\u6211\u4eec\u53d1\u73b0 a \u7684\u7c7b\u578b\u4ece number \u8f6c\u6362\u6210\u4e86 string<\/p>\n

\u8bf4\u660e JavaScript\u00a0\u4e2d\u7684\u53d8\u91cf\u662f\u4e00\u4e2a\u52a8\u6001\u7c7b\u578b\u53d8\u91cf~~<\/p>\n

1) JS \u7684\u53d8\u91cf\u7c7b\u578b\u662f\u7a0b\u5e8f\u8fd0\u884c\u8fc7\u7a0b\u4e2d\u624d\u786e\u5b9a\u7684(\u8fd0\u884c\u5230 = \u8bed\u53e5\u624d\u4f1a\u786e\u5b9a\u7c7b\u578b)<\/h5>\n

var a = 10; \u00a0 \u00a0 \/\/ \u6570\u5b57
\nvar b = "hehe"; \/\/ \u5b57\u7b26\u4e32 <\/p>\n

2) \u968f\u7740\u7a0b\u5e8f\u8fd0\u884c, \u53d8\u91cf\u7684\u7c7b\u578b\u53ef\u80fd\u4f1a\u53d1\u751f\u6539\u53d8.<\/h5>\n

var a = 10; \u00a0 \u00a0\/\/ \u6570\u5b57
\na = "hehe"; \u00a0 \u00a0\/\/ \u5b57\u7b26\u4e32 <\/p>\n

\u8fd9\u4e00\u70b9\u548c C Java \u8fd9\u79cd\u9759\u6001\u7c7b\u578b\u8bed\u8a00\u5dee\u5f02\u8f83\u5927.<\/p>\n

C, C++, Java, Go \u7b49\u8bed\u8a00\u662f\u9759\u6001\u7c7b\u578b\u8bed\u8a00. \u4e00\u4e2a\u53d8\u91cf\u5728\u521b\u5efa\u7684\u65f6\u5019\u7c7b\u578b\u5c31\u786e\u5b9a\u4e86, \u4e0d\u80fd\u5728\u8fd0\u884c\u65f6\u53d1\u751f\u6539\u53d8.<\/p>\n

\u5982\u679c\u5c1d\u8bd5\u6539\u53d8, \u5c31\u4f1a\u76f4\u63a5\u7f16\u8bd1\u62a5\u9519<\/p>\n

\u57fa\u672c\u6570\u636e\u7c7b\u578b<\/h3>\n

JS \u4e2d\u5185\u7f6e\u7684\u51e0\u79cd\u7c7b\u578b<\/p>\n

number: \u6570\u5b57. \u4e0d\u533a\u5206\u6574\u6570\u548c\u5c0f\u6570.<\/p>\n

boolean: true \u771f, false \u5047.<\/p>\n

string: \u5b57\u7b26\u4e32\u7c7b\u578b.<\/p>\n

undefined: \u53ea\u6709\u552f\u4e00\u7684\u503c undefined. \u8868\u793a\u672a\u5b9a\u4e49\u7684\u503c.<\/p>\n

null: \u53ea\u6709\u552f\u4e00\u7684\u503c null. \u8868\u793a\u7a7a\u503c<\/p>\n

number\u6570\u5b57\u7c7b\u578b<\/h4>\n

JS \u4e2d\u4e0d\u533a\u5206\u6574\u6570\u548c\u6d6e\u70b9\u6570, \u7edf\u4e00\u90fd\u4f7f\u7528 "\u6570\u5b57\u7c7b\u578b" \u6765\u8868\u793a<\/p>\n

\u4ee3\u7801\u5c55\u793a👇<\/p>\n

<!DOCTYPE html>
\n<html lang="en">
\n<head>
\n <meta charset="UTF-8">
\n <meta name="viewport" content="width=device-width, initial-scale=1.0">
\n <title>Document<\/title>
\n<\/head>
\n<body>
\n <script>
\n \/\/ a = 1
\n \/\/ console.log(typeof(a))
\n \/\/ b = 'b'
\n \/\/ a = b
\n \/\/ console.log(typeof(a))
\n let a = 10;
\n console.log(typeof(a))
\n a = a \/ 3
\n console.log(a)
\n console.log(typeof(a))
\n <\/script>
\n<\/body>
\n<\/html> <\/p>\n

\u6548\u679c\u5c55\u793a👇<\/p>\n

\"\"<\/p>\n

\u6240\u4ee5 \u4e0d\u7ba1\u662f\u5c0f\u6570\u8fd8\u662f\u6574\u6570，\u7edf\u4e00\u90fd\u662f number \u7c7b\u578b<\/p>\n

\u6570\u5b57\u8fdb\u5236\u8868\u793a<\/h4>\n

\u8ba1\u7b97\u673a\u4e2d\u90fd\u662f\u4f7f\u7528\u4e8c\u8fdb\u5236\u6765\u8868\u793a\u6570\u636e, \u800c\u4eba\u5e73\u65f6\u90fd\u662f\u4f7f\u7528\u5341\u8fdb\u5236.<\/p>\n

\u56e0\u4e3a\u4e8c\u8fdb\u5236\u5728\u4f7f\u7528\u8fc7\u7a0b\u4e2d\u4e0d\u592a\u65b9\u4fbf(01\u592a\u591a\u4f1a\u770b\u82b1\u773c).<\/p>\n

\u6240\u4ee5\u5728\u65e5\u5e38\u4f7f\u7528\u4e8c\u8fdb\u5236\u6570\u5b57\u65f6\u5f80\u5f80\u4f7f\u7528 \u516b\u8fdb\u5236 \u548c \u5341\u516d\u8fdb\u5236 \u6765\u8868\u793a\u4e8c\u8fdb\u5236\u6570\u5b57<\/p>\n

var a = 07; \u00a0 \u00a0 \u00a0\/\/ \u516b\u8fdb\u5236\u6574\u6570, \u4ee5 0 \u5f00\u5934
\nvar b = 0xa; \u00a0 \u00a0 \/\/ \u5341\u516d\u8fdb\u5236\u6574\u6570, \u4ee5 0x \u5f00\u5934
\nvar c = 0b10; \u00a0 \u00a0\/\/ \u4e8c\u8fdb\u5236\u6574\u6570, \u4ee5 0b \u5f00\u5934 <\/p>\n

\u6ce8\u610f:<\/p>\n

\u4e00\u4e2a\u516b\u8fdb\u5236\u6570\u5b57\u5bf9\u5e94\u4e09\u4e2a\u4e8c\u8fdb\u5236\u6570\u5b57<\/p>\n

\u4e00\u4e2a\u5341\u516d\u8fdb\u5236\u6570\u5b57\u5bf9\u5e94\u56db\u4e2a\u4e8c\u8fdb\u5236\u6570\u5b57. (\u4e24\u4e2a\u5341\u516d\u8fdb\u5236\u6570\u5b57\u5c31\u662f\u4e00\u4e2a\u5b57\u8282)<\/p>\n

\u5404\u79cd\u8fdb\u5236\u4e4b\u95f4\u7684\u8f6c\u6362, \u4e0d\u9700\u8981\u624b\u5de5\u8ba1\u7b97, \u76f4\u63a5\u4f7f\u7528\u8ba1\u7b97\u5668\u5373\u53ef<\/p>\n

\u7279\u6b8a\u7684\u6570\u5b57\u503c<\/h4>\n

Infinity: \u65e0\u7a77\u5927, \u5927\u4e8e\u4efb\u4f55\u6570\u5b57. \u8868\u793a\u6570\u5b57\u5df2\u7ecf\u8d85\u8fc7\u4e86 JS \u80fd\u8868\u793a\u7684\u8303\u56f4.<\/p>\n

-Infinity: \u8d1f\u65e0\u7a77\u5927, \u5c0f\u4e8e\u4efb\u4f55\u6570\u5b57. \u8868\u793a\u6570\u5b57\u5df2\u7ecf\u8d85\u8fc7\u4e86 JS \u80fd\u8868\u793a\u7684\u8303\u56f4.<\/p>\n

NaN: \u8868\u793a\u5f53\u524d\u7684\u7ed3\u679c\u4e0d\u662f\u4e00\u4e2a\u6570\u5b57<\/p>\n

var max = Number.MAX_VALUE;
\n\/\/ \u5f97\u5230 Infinity
\nconsole.log(max * 2);
\n\/\/ \u5f97\u5230 -Infinity
\nconsole.log(-max * 2);
\n\/\/ \u5f97\u5230 NaN
\nconsole.log('hehe' – 10); <\/p>\n

\u4ee3\u7801\u5c55\u793a👇<\/p>\n

<!DOCTYPE html>
\n<html lang="en">
\n<head>
\n <meta charset="UTF-8">
\n <meta name="viewport" content="width=device-width, initial-scale=1.0">
\n <title>Document<\/title>
\n<\/head>
\n<body>
\n <script>
\n let a = 10
\n console.log(10\/0)
\n <\/script>
\n<\/body>
\n<\/html> <\/p>\n

\u6548\u679c\u5c55\u793a👇<\/p>\n

\"\"<\/p>\n

\u6211\u4eec\u53d1\u73b0，\u5982\u679c\u662f\u5728 Java \u4e2d，10 \/ 0 \u539f\u672c\u4f1a\u629b\u51fa\u5f02\u5e38\u7684\u4ee3\u7801，\u5728 JavaScript \u4e2d\u5374\u662f\u6253\u5370\u51fa\u4e86\u4e00\u4e2a Infinity<\/p>\n

\u8d1f\u65e0\u7a77\u65e0\u975e\u5c31\u662f\u5728\u524d\u9762\u52a0\u4e86\u4e2a\u201d – "，\u8fd9\u91cc\u5c31\u4e0d\u6f14\u793a\u4e86<\/p>\n

\u4e0b\u9762\u6f14\u793a\u4e00\u4e0b NaN 👇<\/p>\n

<!DOCTYPE html>
\n<html lang="en">
\n<head>
\n <meta charset="UTF-8">
\n <meta name="viewport" content="width=device-width, initial-scale=1.0">
\n <title>Document<\/title>
\n<\/head>
\n<body>
\n <script>
\n let a = 10
\n console.log("hahah"-1)
\n <\/script>
\n<\/body>
\n<\/html> <\/p>\n

\u6548\u679c\u5c55\u793a👇<\/p>\n

\"\"<\/p>\n

\u6ce8\u610f:<\/p>\n

1. \u8d1f\u65e0\u7a77\u5927 \u548c \u65e0\u7a77\u5c0f \u4e0d\u662f\u4e00\u56de\u4e8b. \u65e0\u7a77\u5c0f\u6307\u65e0\u9650\u8d8b\u8fd1\u4e0e 0, \u503c\u4e3a 1 \/ Infinity<\/p>\n

2. 'hehe' + 10 \u5f97\u5230\u7684\u4e0d\u662f NaN, \u800c\u662f 'hehe10', \u4f1a\u628a\u6570\u5b57\u9690\u5f0f\u8f6c\u6210\u5b57\u7b26\u4e32, \u518d\u8fdb\u884c\u5b57\u7b26\u4e32\u62fc\u63a5.<\/p>\n

3. \u53ef\u4ee5\u4f7f\u7528 isNaN \u51fd\u6570\u5224\u5b9a\u662f\u4e0d\u662f\u4e00\u4e2a\u975e\u6570\u5b57.<\/p>\n

console.log(isNaN(10)); \u00a0\/\/ false
\nconsole.log(isNaN('hehe' – 10)); \u00a0\/\/ true <\/p>\n

string\u5b57\u7b26\u4e32\u7c7b\u578b<\/h4>\n

\u57fa\u672c\u89c4\u5219<\/h5>\n

\u5b57\u7b26\u4e32\u5b57\u9762\u503c\u9700\u8981\u4f7f\u7528\u5f15\u53f7\u5f15\u8d77\u6765, \u5355\u5f15\u53f7\u53cc\u5f15\u53f7\u5747\u53ef<\/p>\n

var a = "haha";
\nvar b = 'hehe';
\nvar c = hehe; \u00a0 \u00a0\/\/ \u8fd0\u884c\u51fa\u9519 <\/p>\n

\u5982\u679c\u5b57\u7b26\u4e32\u4e2d\u672c\u6765\u5df2\u7ecf\u5305\u542b\u5f15\u53f7\u548b\u529e?<\/p>\n

var msg = "My name is "zhangsan""; \u00a0 \u00a0\/\/ \u51fa\u9519
\nvar msg = "My name is \\\\"zhangsan\\\\""; \u00a0\/\/ \u6b63\u786e, \u4f7f\u7528\u8f6c\u4e49\u5b57\u7b26. \\\\" \u6765\u8868\u793a\u5b57\u7b26\u4e32\u5185\u90e8\u7684\u5f15\u53f7.
\nvar msg = "My name is 'zhangsan'"; \u00a0 \u00a0\/\/ \u6b63\u786e, \u642d\u914d\u4f7f\u7528\u5355\u53cc\u5f15\u53f7
\nvar msg = 'My name is "zhangsan"'; \u00a0 \u00a0\/\/ \u6b63\u786e, \u642d\u914d\u4f7f\u7528\u5355\u53cc\u5f15\u53f7 <\/p>\n

\u4ee3\u7801\u5c55\u793a👇<\/p>\n

let a = '\u54c8\u54c8\u54c8'
\n a = "JS"
\n a = '\u54c8\u54c8\u54c8"JS"'
\n alert(a) <\/p>\n

\u6548\u679c\u5c55\u793a👇<\/p>\n

\"\"<\/p>\n

\u5982\u679c\u5355\u5f15\u53f7\u548c\u53cc\u5f15\u53f7\u4e92\u6362\u4f4d\u7f6e，\u518d\u6765\u770b👇<\/p>\n

let a = '\u54c8\u54c8\u54c8'
\n a = "JS"
\n a = "\u54c8\u54c8\u54c8'JS'"
\n alert(a) <\/p>\n

\u6548\u679c\u5c55\u793a👇<\/p>\n

\"\"<\/p>\n

\u8f6c\u4e49\u5b57\u7b26<\/h5>\n

\u6709\u4e9b\u5b57\u7b26\u4e0d\u65b9\u4fbf\u76f4\u63a5\u8f93\u5165, \u4e8e\u662f\u8981\u901a\u8fc7\u4e00\u4e9b\u7279\u6b8a\u65b9\u5f0f\u6765\u8868\u793a（\u4e0e Java \u7c7b\u4f3c）<\/p>\n

\\\\n
\n\\\\\\\\
\n\\\\'
\n\\\\"
\n\\\\t <\/p>\n

\u6c42\u957f\u5ea6<\/h5>\n

\u4f7f\u7528 String \u7684 length \u5c5e\u6027\u5373\u53ef<\/p>\n

var a = 'hehe';
\nconsole.log(a.length);
\nvar b = '\u54c8\u54c8';
\nconsole.log(b.length); <\/p>\n

\u7ed3\u679c:<\/p>\n

4
\n2 <\/p>\n

\u5355\u4f4d\u4e3a\u5b57\u7b26\u7684\u6570\u91cf<\/p>\n

\u5b57\u7b26\u4e32\u62fc\u63a5<\/h5>\n

\u4f7f\u7528 + \u8fdb\u884c\u62fc\u63a5<\/p>\n

var a = "my name is ";
\nvar b = "CoderYanger";
\nconsole.log(a + b); <\/p>\n

\u6548\u679c\u5c55\u793a👇<\/p>\n

\"\"<\/p>\n

\u6ce8\u610f, \u6570\u5b57\u548c\u5b57\u7b26\u4e32\u4e5f\u53ef\u4ee5\u8fdb\u884c\u62fc\u63a5<\/p>\n

var c = "my score is ";
\nvar d = 100;
\nconsole.log(c + d); <\/p>\n

\u6548\u679c\u5c55\u793a👇<\/p>\n

\"\"<\/p>\n

\u6ce8\u610f, \u8981\u8ba4\u51c6\u76f8\u52a0\u7684\u53d8\u91cf\u5230\u5e95\u662f\u5b57\u7b26\u4e32\u8fd8\u662f\u6570\u5b57<\/p>\n

console.log(100 + 100); \u00a0 \u00a0 \/\/ 200
\nconsole.log('100' + 100); \u00a0 \/\/ 100100 <\/p>\n

\u6548\u679c\u5c55\u793a👇<\/p>\n

\"\"<\/p>\n

\u53ef\u89c1，\u6548\u679c\u4e0e Java \u662f\u7c7b\u4f3c\u7684~~<\/p>\n

boolean\u5e03\u5c14\u7c7b\u578b<\/h4>\n

\u8868\u793a "\u771f" \u548c "\u5047"<\/p>\n

boolean \u539f\u672c\u662f\u6570\u5b66\u4e2d\u7684\u6982\u5ff5 (\u5e03\u5c14\u4ee3\u6570).<\/p>\n

\u5728\u8ba1\u7b97\u673a\u4e2d boolean \u610f\u4e49\u91cd\u5927, \u5f80\u5f80\u8981\u642d\u914d\u6761\u4ef6\/\u5faa\u73af\u5b8c\u6210\u903b\u8f91\u5224\u65ad<\/p>\n

Boolean \u53c2\u4e0e\u8fd0\u7b97\u65f6\u5f53\u505a 1 \u548c 0 \u6765\u770b\u5f85<\/p>\n

console.log(true + 1);
\nconsole.log(false + 1) <\/p>\n

\u8fd9\u6837\u7684\u64cd\u4f5c\u5176\u5b9e\u662f\u4e0d\u79d1\u5b66\u7684. \u5b9e\u9645\u5f00\u53d1\u4e2d\u4e0d\u5e94\u8be5\u8fd9\u4e48\u5199<\/p>\n

\u4ee3\u7801\u5c55\u793a👇<\/p>\n

let a = true
\n console.log(typeof(a))
\n a = a + 1
\n console.log("a\u7684\u503c\u7b49\u4e8e" + a + ",a\u7684\u7c7b\u578b" + typeof(a)) <\/p>\n

\u6548\u679c\u5c55\u793a👇<\/p>\n

\"\"<\/p>\n

undefined\u672a\u5b9a\u4e49\u6570\u636e\u7c7b\u578b<\/h4>\n

\u5982\u679c\u4e00\u4e2a\u53d8\u91cf\u6ca1\u6709\u88ab\u521d\u59cb\u5316\u8fc7, \u672a\u88ab\u5b9a\u4e49，\u7ed3\u679c\u5c31\u662f undefined, \u662f undefined \u7c7b\u578b<\/p>\n

let a;
\nconsole.log(a) <\/p>\n

\u6548\u679c\u5c55\u793a👇<\/p>\n

\"\"<\/p>\n

undefined \u548c\u5b57\u7b26\u4e32\u8fdb\u884c\u76f8\u52a0, \u7ed3\u679c\u8fdb\u884c\u5b57\u7b26\u4e32\u62fc\u63a5<\/p>\n

console.log(a + "10"); \u00a0\/\/ undefined10 <\/p>\n

\u6548\u679c\u5c55\u793a👇<\/p>\n

\"\"<\/p>\n

undefined \u548c\u6570\u5b57\u8fdb\u884c\u76f8\u52a0, \u7ed3\u679c\u4e3a NaN<\/p>\n

console.log(a + 10);\/\/NaN
\nconsole.log(a + true);\/\/NaN <\/p>\n

\u6548\u679c\u5c55\u793a\u4e0b👇<\/p>\n

\"\"<\/p>\n

null\u7a7a\u503c\u7c7b\u578b<\/h4>\n

\u00a0null \u8868\u793a\u5f53\u524d\u7684\u53d8\u91cf\u662f\u4e00\u4e2a "\u7a7a\u503c".<\/p>\n

var b = null;
\nconsole.log(b + 10); \u00a0 \u00a0\/\/ 10
\nconsole.log(b + "10"); \u00a0\/\/ null10 <\/p>\n

\u6548\u679c\u5c55\u793a👇<\/p>\n

\"\"<\/p>\n

\u6ce8\u610f: <\/p>\n

null \u548c undefined \u90fd\u8868\u793a\u53d6\u503c\u975e\u6cd5\u7684\u60c5\u51b5, \u4f46\u662f\u4fa7\u91cd\u70b9\u4e0d\u540c.<\/p>\n

null \u8868\u793a\u5f53\u524d\u7684\u503c\u4e3a\u7a7a. (\u76f8\u5f53\u4e8e\u6709\u4e00\u4e2a\u7a7a\u7684\u76d2\u5b50)<\/p>\n

undefined \u8868\u793a\u5f53\u524d\u7684\u53d8\u91cf\u672a\u5b9a\u4e49. (\u76f8\u5f53\u4e8e\u8fde\u76d2\u5b50\u90fd\u6ca1\u6709)<\/p>\n

\u8fd0\u7b97\u7b26<\/h3>\n

JavaScript \u4e2d\u7684\u8fd0\u7b97\u7b26\u548c Java \u7528\u6cd5\u57fa\u672c\u76f8\u540c. \u6b64\u5904\u4e0d\u505a\u8be6\u7ec6\u4ecb\u7ecd\u4e86.<\/p>\n

\u7b97\u672f\u8fd0\u7b97\u7b26<\/h4>\n

+<\/p>\n

–<\/p>\n

*<\/p>\n

\/<\/p>\n

%<\/p>\n

\u8d4b\u503c\u8fd0\u7b97\u7b26&\u590d\u5408\u8d4b\u503c\u8fd0\u7b97\u7b26<\/h4>\n

=<\/p>\n

+=<\/p>\n

-=<\/p>\n

*=<\/p>\n

\/=<\/p>\n

%=<\/p>\n

\u81ea\u589e\u81ea\u51cf\u8fd0\u7b97\u7b26<\/h4>\n

++: \u81ea\u589e1<\/p>\n

–: \u81ea\u51cf<\/p>\n

\u6bd4\u8f83\u8fd0\u7b97\u7b26<\/h4>\n

<<\/p>\n

><\/p>\n

<=<\/p>\n

>=<\/p>\n

== \u6bd4\u8f83\u76f8\u7b49(\u4f1a\u8fdb\u884c\u9690\u5f0f\u7c7b\u578b\u8f6c\u6362)（\u6bd4\u8f83\u7684\u662f\u53d8\u91cf\u7684\u5185\u5bb9）<\/p>\n

!=<\/p>\n

=== \u6bd4\u8f83\u76f8\u7b49(\u4e0d\u4f1a\u8fdb\u884c\u9690\u5f0f\u7c7b\u578b\u8f6c\u6362)（\u6bd4\u8f83\u7684\u662f\u5185\u5bb9+\u6570\u636e\u7c7b\u578b）<\/p>\n

!==<\/p>\n

\u4ee3\u7801\u5c55\u793a👇<\/p>\n

let a = 10;
\n let b = "10";
\n alert(a==b) <\/p>\n

\u6548\u679c\u5c55\u793a👇<\/p>\n

\"\"<\/p>\n

\u00a0\u4ee3\u7801\u5c55\u793a👇<\/p>\n

let a = 10;
\n let b = "10";
\n alert(a===b) <\/p>\n

\u6548\u679c\u5c55\u793a👇<\/p>\n

\"\"<\/p>\n

\u903b\u8f91\u8fd0\u7b97\u7b26<\/h4>\n

\u7528\u4e8e\u8ba1\u7b97\u591a\u4e2a boolean \u8868\u8fbe\u5f0f\u7684\u503c.<\/p>\n

&& \u4e0e: \u4e00\u5047\u5219\u5047<\/p>\n

|| \u6216: \u4e00\u771f\u5219\u771f<\/p>\n

! \u975e<\/p>\n

\u4f4d\u8fd0\u7b97<\/h4>\n

& \u6309\u4f4d\u4e0e<\/p>\n

| \u6309\u4f4d\u6216<\/p>\n

~ \u6309\u4f4d\u53d6\u53cd<\/p>\n

^ \u6309\u4f4d\u5f02\u6216<\/p>\n

\u79fb\u4f4d\u8fd0\u7b97<\/h4>\n

<< \u5de6\u79fb<\/p>\n

>> \u6709\u7b26\u53f7\u53f3\u79fb(\u7b97\u672f\u53f3\u79fb)<\/p>\n

>>> \u65e0\u7b26\u53f7\u53f3\u79fb(\u903b\u8f91\u53f3\u79fb)<\/p>\n

\u6761\u4ef6\u8bed\u53e5<\/h3>\n

\u4e0e Java \u90fd\u662f\u4e00\u6837\u7684~~<\/p>\n

if\u8bed\u53e5<\/h4>\n

\u57fa\u672c\u8bed\u6cd5\u683c\u5f0f<\/h5>\n

\u6761\u4ef6\u8868\u8fbe\u5f0f\u4e3a true, \u5219\u6267\u884c if \u7684 { } \u4e2d\u7684\u4ee3\u7801<\/p>\n

\/\/ \u5f62\u5f0f1
\nif (\u6761\u4ef6) {
\n \u00a0 \u00a0\u8bed\u53e5
\n}
\n\/\/ \u5f62\u5f0f2
\nif (\u6761\u4ef6) {
\n \u00a0 \u00a0\u8bed\u53e51
\n} else {
\n \u00a0 \u00a0\u8bed\u53e52
\n}
\n\/\/ \u5f62\u5f0f3
\nif (\u6761\u4ef61) {
\n \u00a0 \u00a0\u8bed\u53e51
\n} else if (\u6761\u4ef62) {
\n \u00a0 \u00a0\u8bed\u53e52 \u00a0
\n} else if …. {
\n \u00a0 \u00a0\u8bed\u53e5…
\n} else {
\n \u00a0 \u00a0\u8bed\u53e5N
\n} <\/p>\n

\u7ec3\u4e60\u6848\u4f8b<\/h5>\n
\u4ee3\u7801\u793a\u4f8b1：\u5224\u5b9a\u4e00\u4e2a\u6570\u5b57\u662f\u5947\u6570\u8fd8\u662f\u5076\u6570<\/h5>\n

\/\/\u5224\u65ad\u5f53\u524d\u6570\u5b57\u662f\u5947\u6570\u8fd8\u662f\u5076\u6570
\n let num = prompt("\u8bf7\u8f93\u5165\u6570\u5b57")
\n if(num%2==0) alert("\u8fd9\u4e2a\u6570\u5b57\u662f\u5076\u6570")
\n else if(num%2==1) alert("\u8fd9\u4e2a\u6570\u5b57\u662f\u5947\u6570")
\n else alert("\u975e\u6cd5\u8f93\u5165") <\/p>\n

\u6548\u679c\u5c55\u793a👇<\/p>\n

\"\"<\/p>\n

\"\"<\/p>\n

\u6ce8\u610f! \u4e0d\u80fd\u5199\u6210 num % 2 == 1 \u5c31\u662f\u5947\u6570. \u8d1f\u7684\u5947\u6570 % 2 \u7ed3\u679c\u53ef\u80fd\u662f -1.<\/p>\n

\u4ee3\u7801\u793a\u4f8b2：\u5224\u5b9a\u4e00\u4e2a\u6570\u5b57\u662f\u6b63\u6570\u8fd8\u662f\u8d1f\u6570<\/h5>\n

var num = 10;
\nif (num > 0) {
\n \u00a0 \u00a0console.log("num \u662f\u6b63\u6570");
\n} else if (num < 0) {
\n \u00a0 \u00a0console.log("num \u662f\u8d1f\u6570");
\n} else {
\n \u00a0 \u00a0console.log("num \u662f 0");
\n} <\/p>\n

\u4ee3\u7801\u793a\u4f8b3：\u5224\u5b9a\u67d0\u4e00\u5e74\u4efd\u662f\u5426\u662f\u95f0\u5e74<\/h5>\n

var year = 2000;
\nif (year % 100 == 0) {
\n \u00a0 \u00a0\/\/ \u5224\u5b9a\u4e16\u7eaa\u95f0\u5e74
\n \u00a0 \u00a0if (year % 400 == 0) {
\n \u00a0 \u00a0 \u00a0 \u00a0console.log("\u662f\u95f0\u5e74");
\n \u00a0 } else {
\n \u00a0 \u00a0 \u00a0 \u00a0console.log("\u4e0d\u662f\u95f0\u5e74");
\n \u00a0 }
\n} else {
\n \u00a0 \u00a0\/\/ \u666e\u901a\u95f0\u5e74
\n \u00a0 \u00a0if (year % 4 == 0) {
\n \u00a0 \u00a0 \u00a0 \u00a0console.log("\u662f\u95f0\u5e74");
\n \u00a0 } else {
\n \u00a0 \u00a0 \u00a0 \u00a0console.log("\u4e0d\u662f\u95f0\u5e74");
\n \u00a0 }
\n} <\/p>\n

\u4e09\u5143\u8868\u8fbe\u5f0f<\/h4>\n

\u662f if else \u7684\u7b80\u5316\u5199\u6cd5.<\/p>\n

\u6761\u4ef6 ? \u8868\u8fbe\u5f0f1 : \u8868\u8fbe\u5f0f2<\/p>\n

\u6761\u4ef6\u4e3a\u771f, \u8fd4\u56de\u8868\u8fbe\u5f0f1 \u7684\u503c. \u6761\u4ef6\u4e3a\u5047, \u8fd4\u56de\u8868\u8fbe\u5f0f2 \u7684\u503c.<\/p>\n

\u4ee3\u7801\u5c55\u793a👇<\/p>\n

alert(1 === "1"?true:false) <\/p>\n

\u6548\u679c\u5c55\u793a👇<\/p>\n

\"\"<\/p>\n

\u6ce8\u610f, \u4e09\u5143\u8868\u8fbe\u5f0f\u7684\u4f18\u5148\u7ea7\u662f\u6bd4\u8f83\u4f4e\u7684.<\/p>\n

switch<\/h4>\n

\u66f4\u9002\u5408\u591a\u5206\u652f\u7684\u573a\u666f<\/p>\n

switch (\u8868\u8fbe\u5f0f) {
\n \u00a0 \u00a0case \u503c1:
\n \u00a0 \u00a0 \u00a0 \u00a0\u8bed\u53e51;
\n \u00a0 \u00a0 \u00a0 \u00a0break;
\n \u00a0 \u00a0case \u503c2:
\n \u00a0 \u00a0 \u00a0 \u00a0\u8bed\u53e52:
\n \u00a0 \u00a0 \u00a0 \u00a0break;
\n \u00a0 \u00a0default:
\n \u00a0 \u00a0 \u00a0 \u00a0\u8bed\u53e5N;
\n} <\/p>\n

\u7528\u6237\u8f93\u5165\u4e00\u4e2a\u6574\u6570, \u63d0\u793a\u4eca\u5929\u662f\u661f\u671f\u51e0<\/p>\n

var day = prompt("\u8bf7\u8f93\u5165\u4eca\u5929\u661f\u671f\u51e0: ");\/\/\u9ed8\u8ba4\u662fstring\u7c7b\u578b
\nswitch (parseInt(day)) {\/\/\u6b64\u5904\u9700\u8981\u7528parseInt()\u8f6c\u6362\u6210\u6574\u6570，\u5426\u5219\u662fstring\u7c7b\u578b
\n \u00a0 \u00a0case 1:
\n \u00a0 \u00a0 \u00a0 \u00a0console.log("\u661f\u671f\u4e00");
\n \u00a0 \u00a0 \u00a0 \u00a0break;
\n \u00a0 \u00a0case 2:
\n \u00a0 \u00a0 \u00a0 \u00a0console.log("\u661f\u671f\u4e8c");
\n\u00a0 \u00a0break;
\n \u00a0 \u00a0case 3:
\n \u00a0 \u00a0 \u00a0 \u00a0console.log("\u661f\u671f\u4e09");
\n \u00a0 \u00a0 \u00a0 \u00a0break;
\n \u00a0 \u00a0case 4:
\n \u00a0 \u00a0 \u00a0 \u00a0console.log("\u661f\u671f\u56db");
\n \u00a0 \u00a0 \u00a0 \u00a0break;
\n \u00a0 \u00a0case 5:
\n \u00a0 \u00a0 \u00a0 \u00a0console.log("\u661f\u671f\u4e94");
\n \u00a0 \u00a0 \u00a0 \u00a0break;
\n \u00a0 \u00a0case 6:
\n \u00a0 \u00a0 \u00a0 \u00a0console.log("\u661f\u671f\u516d");
\n \u00a0 \u00a0 \u00a0 \u00a0break;
\n \u00a0 \u00a0case 7:
\n \u00a0 \u00a0 \u00a0 \u00a0console.log("\u661f\u671f\u65e5");
\n \u00a0 \u00a0 \u00a0 \u00a0break;
\n \u00a0 \u00a0default:
\n \u00a0 \u00a0 \u00a0 \u00a0console.log("\u8f93\u5165\u6709\u8bef");
\n} <\/p>\n

\u8c03\u8bd5\u6280\u5de7<\/span><\/h5>\n

\u2460\u70b9\u51fb\u884c\u53f7=\u6253\u65ad\u70b9<\/p>\n

\"\"<\/p>\n

\u2461\u5237\u65b0\u9875\u9762\u540e，\u8fdb\u5165 DeBug \u8c03\u8bd5\u6a21\u5f0f<\/p>\n

\"\"<\/p>\n

\u2462\u5feb\u6377\u952e：<\/p>\n

F8：\u7ee7\u7eed\u8fd0\u884c<\/p>\n

F10：\u5355\u6b65\u8df3\u8fc7<\/p>\n

F11：\u5355\u6b65\u8fdb\u5165<\/p>\n

shift+F11：\u5355\u6b65\u8df3\u51fa，\u7ed3\u675f\u8c03\u8bd5<\/p>\n

\u5faa\u73af\u8bed\u53e5<\/h3>\n

\u91cd\u590d\u6267\u884c\u67d0\u4e9b\u8bed\u53e5<\/p>\n

while\u5faa\u73af<\/h4>\n

while (\u6761\u4ef6) {
\n \u00a0 \u00a0\u5faa\u73af\u4f53;
\n} <\/p>\n

\u6267\u884c\u8fc7\u7a0b:<\/p>\n

\u5148\u6267\u884c\u6761\u4ef6\u8bed\u53e5<\/p>\n

\u6761\u4ef6\u4e3a true, \u6267\u884c\u5faa\u73af\u4f53\u4ee3\u7801.<\/p>\n

\u6761\u4ef6\u4e3a false, \u76f4\u63a5\u7ed3\u675f\u5faa\u73af<\/p>\n

\u4ee3\u7801\u793a\u4f8b1：\u6253\u53701-10<\/h5>\n

var num = 1;
\nwhile (num <= 10) {
\n \u00a0 \u00a0console.log(num);
\n \u00a0 \u00a0num++;
\n} <\/p>\n

\u4ee3\u7801\u793a\u4f8b2：\u8ba1\u7b975\u7684\u9636\u4e58<\/h5>\n

var result = 1;
\nvar i = 1;
\nwhile (i <= 5) {
\n \u00a0 \u00a0result *= i;
\n \u00a0 \u00a0i++;
\n}
\nconsole.log(result) <\/p>\n

continue<\/h4>\n

\u7ed3\u675f\u8fd9\u6b21\u5faa\u73af<\/p>\n

\u00a0\u5403\u4e94\u4e2a\u674e\u5b50, \u53d1\u73b0\u7b2c\u4e09\u4e2a\u674e\u5b50\u91cc\u6709\u4e00\u53ea\u866b\u5b50, \u4e8e\u662f\u6254\u6389\u8fd9\u4e2a, \u7ee7\u7eed\u5403\u4e0b\u4e00\u4e2a\u674e\u5b50<\/p>\n

var i = 1;
\nwhile (i <= 5) {
\n \u00a0 \u00a0if (i == 3) {
\n \u00a0 \u00a0 \u00a0 \u00a0i++;
\n \u00a0 \u00a0 \u00a0 \u00a0continue;
\n \u00a0 }
\n \u00a0 \u00a0console.log("\u6211\u5728\u5403\u7b2c" + i + "\u4e2a\u674e\u5b50");
\n \u00a0 \u00a0i++;
\n} <\/p>\n

\u6211\u5728\u5403\u7b2c1\u4e2a\u674e\u5b50<\/p>\n

\u6211\u5728\u5403\u7b2c2\u4e2a\u674e\u5b50<\/p>\n

\u6211\u5728\u5403\u7b2c4\u4e2a\u674e\u5b50<\/p>\n

\u6211\u5728\u5403\u7b2c5\u4e2a\u674e\u5b50<\/p>\n

\u4ee3\u7801\u793a\u4f8b：\u627e\u5230100-200\u4e2d\u6240\u67093\u7684\u500d\u6570<\/h5>\n

var num = 100;
\nwhile (num <= 200) {
\n \u00a0 \u00a0if (num % 3 != 0) {
\n \u00a0 \u00a0 \u00a0 \u00a0num++; \u00a0\/\/ \u8fd9\u91cc\u7684 ++ \u4e0d\u8981\u5fd8\u8bb0! \u5426\u5219\u4f1a\u6b7b\u5faa\u73af.
\n \u00a0 \u00a0 \u00a0 \u00a0continue;
\n \u00a0 }
\n \u00a0 \u00a0console.log("\u627e\u5230\u4e86 3 \u7684\u500d\u6570, \u4e3a:" + num);
\n \u00a0 \u00a0num++;
\n} <\/p>\n

break<\/h4>\n

\u7ed3\u675f\u6574\u4e2a\u5faa\u73af<\/p>\n

\u5403\u4e94\u4e2a\u674e\u5b50, \u53d1\u73b0\u7b2c\u4e09\u4e2a\u674e\u5b50\u91cc\u6709\u534a\u4e2a\u866b\u5b50, \u4e8e\u662f\u5269\u4e0b\u7684\u4e5f\u4e0d\u5403\u4e86<\/p>\n

\u4ee3\u7801\u793a\u4f8b：\u627e\u5230100-200\u4e2d\u7b2c\u4e00\u4e2a3\u7684\u500d\u6570<\/h5>\n

var i = 1;
\nwhile (i <= 5) {
\n \u00a0 \u00a0if (i == 3) {
\n \u00a0 \u00a0 \u00a0 \u00a0break;
\n \u00a0 }
\n \u00a0 \u00a0console.log("\u6211\u5728\u5403\u7b2c" + i + "\u4e2a\u674e\u5b50");
\n \u00a0 \u00a0i++;
\n} <\/p>\n

\u6211\u5728\u5403\u7b2c1\u4e2a\u674e\u5b50<\/p>\n

\u6211\u5728\u5403\u7b2c2\u4e2a\u674e\u5b50<\/p>\n

for\u5faa\u73af<\/h4>\n

for (\u8868\u8fbe\u5f0f1; \u8868\u8fbe\u5f0f2; \u8868\u8fbe\u5f0f3) {
\n \u5faa\u73af\u4f53
\n} <\/p>\n

\u8868\u8fbe\u5f0f1: \u7528\u4e8e\u521d\u59cb\u5316\u5faa\u73af\u53d8\u91cf.<\/p>\n

\u8868\u8fbe\u5f0f2: \u5faa\u73af\u6761\u4ef6<\/p>\n

\u8868\u8fbe\u5f0f3: \u66f4\u65b0\u5faa\u73af\u53d8\u91cf.<\/p>\n

\u6267\u884c\u8fc7\u7a0b:<\/p>\n

\u5148\u6267\u884c\u8868\u8fbe\u5f0f1, \u521d\u59cb\u5316\u5faa\u73af\u53d8\u91cf<\/p>\n

\u518d\u6267\u884c\u8868\u8fbe\u5f0f2, \u5224\u5b9a\u5faa\u73af\u6761\u4ef6<\/p>\n

\u5982\u679c\u6761\u4ef6\u4e3a false, \u7ed3\u675f\u5faa\u73af<\/p>\n

\u5982\u679c\u6761\u4ef6\u4e3a true, \u5219\u6267\u884c\u5faa\u73af\u4f53\u4ee3\u7801.<\/p>\n

\u6267\u884c\u8868\u8fbe\u5f0f3 \u66f4\u65b0\u5faa\u73af\u53d8\u91cf<\/p>\n

\u4ee3\u7801\u793a\u4f8b1：\u6253\u53701-10\u7684\u6570\u5b57<\/h5>\n

for (var num = 1; num <= 10; num++) {
\n \u00a0 \u00a0console.log(num);
\n} <\/p>\n

\u4ee3\u7801\u793a\u4f8b2：\u8ba1\u7b975\u7684\u9636\u4e58<\/h5>\n

var result = 0;
\nfor (var i = 1; i <= 5; i++) {
\n \u00a0 \u00a0result *= i;
\n}
\nconsole.log("result = " + result); <\/p>\n

\u4ee3\u7801\u793a\u4f8b👇<\/p>\n

for(i = 100;i <= 200; i++){
\n if(i%3==0)
\n break;
\n }
\n alert("100~200\u4e4b\u95f4\u7b2c\u4e00\u4e2a3\u7684\u500d\u6570\u662f"+i) <\/p>\n

\u6548\u679c\u5c55\u793a👇<\/p>\n

\"\"<\/p>\n

\u7ec6\u8282：\u5f53\u5728 i \u524d\u9762\u52a0\u4e0a let \u65f6 i \u7684\u4f5c\u7528\u57df\u5c31\u4ece\u5168\u5c40\u53d8\u6210\u5c40\u90e8\u4e86，\u65e0\u6cd5\u6b63\u5e38\u8f93\u51fa\u4e86👇<\/p>\n

for(let i = 100;i <= 200; i++){
\n if(i%3==0)
\n break;
\n }
\n alert("100~200\u4e4b\u95f4\u7b2c\u4e00\u4e2a3\u7684\u500d\u6570\u662f"+i) <\/p>\n

\"\"<\/p>\n","protected":false},"excerpt":{"rendered":"

\u76ee\u5f55
\n\u521d\u8bc6JavaScript
\nJavaScript\u662f\u4ec0\u4e48
\n\u53d1\u5c55\u5386\u53f2
\nJavaScript\u548cHTML\u548cCSS\u4e4b\u95f4\u7684\u5173\u7cfb
\nJavaScript\u8fd0\u884c\u8fc7\u7a0b
\nJavaScript\u7684\u7ec4\u6210
\n\u91cd\u8981\u6982\u5ff5: ECMAScript
\n\u524d\u7f6e\u77e5\u8bc6
\n\u7b2c\u4e00\u4e2a\u7a0b\u5e8f
\nJavaScript\u7684\u4e66\u5199\u5f62\u5f0f
\n\u884c\u5185\u5f0f
\n\u5185\u5d4c\u5f0f
\n\u5916\u90e8\u5f0f
\n\u6ce8\u91ca
\n\u8f93\u5165\u8f93\u51fa
\n\u8f93\u5165：prompt
\n\u8f93\u51fa：alert
\n\u8f93\u51fa：console.log
\n\u91cd\u8981\u6982\u5ff5：\u65e5<\/p>\n","protected":false},"author":2,"featured_media":100578,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[10655,99,187,87,190,427],"topic":[],"class_list":["post-100598","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-server","tag-agent","tag-java","tag-javascript","tag-87","tag-190","tag-427"],"yoast_head":"\n\u524d\u7aef\u57fa\u7840\u2014\u2014JavaScript\uff08\u57fa\u7840\u8bed\u6cd5\uff09\uff08\u4e0a\u7bc7\uff09 - \u7f51\u7855\u4e92\u8054\u5e2e\u52a9\u4e2d\u5fc3<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/www.wsisp.com\/helps\/100598.html\" \/>\n<meta property=\"og:locale\" content=\"zh_CN\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"\u524d\u7aef\u57fa\u7840\u2014\u2014JavaScript\uff08\u57fa\u7840\u8bed\u6cd5\uff09\uff08\u4e0a\u7bc7\uff09 - \u7f51\u7855\u4e92\u8054\u5e2e\u52a9\u4e2d\u5fc3\" \/>\n<meta property=\"og:description\" content=\"\u76ee\u5f55 \u521d\u8bc6JavaScript JavaScript\u662f\u4ec0\u4e48 \u53d1\u5c55\u5386\u53f2 JavaScript\u548cHTML\u548cCSS\u4e4b\u95f4\u7684\u5173\u7cfb JavaScript\u8fd0\u884c\u8fc7\u7a0b JavaScript\u7684\u7ec4\u6210 \u91cd\u8981\u6982\u5ff5: ECMAScript \u524d\u7f6e\u77e5\u8bc6 \u7b2c\u4e00\u4e2a\u7a0b\u5e8f JavaScript\u7684\u4e66\u5199\u5f62\u5f0f \u884c\u5185\u5f0f \u5185\u5d4c\u5f0f \u5916\u90e8\u5f0f \u6ce8\u91ca \u8f93\u5165\u8f93\u51fa \u8f93\u5165：prompt \u8f93\u51fa：alert \u8f93\u51fa：console.log \u91cd\u8981\u6982\u5ff5：\u65e5\" \/>\n<meta property=\"og:url\" content=\"https:\/\/www.wsisp.com\/helps\/100598.html\" \/>\n<meta property=\"og:site_name\" content=\"\u7f51\u7855\u4e92\u8054\u5e2e\u52a9\u4e2d\u5fc3\" \/>\n<meta property=\"article:published_time\" content=\"2026-09-04T13:18:11+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/www.wsisp.com\/helps\/wp-content\/uploads\/2026\/09\/20260904131802-6a9ac50aa924f.png\" \/>\n<meta name=\"author\" content=\"admin\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"\u4f5c\u8005\" \/>\n\t<meta name=\"twitter:data1\" content=\"admin\" \/>\n\t<meta name=\"twitter:label2\" content=\"\u9884\u8ba1\u9605\u8bfb\u65f6\u95f4\" \/>\n\t<meta name=\"twitter:data2\" content=\"8 \u5206\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\/\/schema.org\",\"@graph\":[{\"@type\":\"WebPage\",\"@id\":\"https:\/\/www.wsisp.com\/helps\/100598.html\",\"url\":\"https:\/\/www.wsisp.com\/helps\/100598.html\",\"name\":\"\u524d\u7aef\u57fa\u7840\u2014\u2014JavaScript\uff08\u57fa\u7840\u8bed\u6cd5\uff09\uff08\u4e0a\u7bc7\uff09 - \u7f51\u7855\u4e92\u8054\u5e2e\u52a9\u4e2d\u5fc3\",\"isPartOf\":{\"@id\":\"https:\/\/www.wsisp.com\/helps\/#website\"},\"datePublished\":\"2026-09-04T13:18:11+00:00\",\"dateModified\":\"2026-09-04T13:18:11+00:00\",\"author\":{\"@id\":\"https:\/\/www.wsisp.com\/helps\/#\/schema\/person\/358e386c577a3ab51c4493330a20ad41\"},\"breadcrumb\":{\"@id\":\"https:\/\/www.wsisp.com\/helps\/100598.html#breadcrumb\"},\"inLanguage\":\"zh-Hans\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\/\/www.wsisp.com\/helps\/100598.html\"]}]},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\/\/www.wsisp.com\/helps\/100598.html#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"\u9996\u9875\",\"item\":\"https:\/\/www.wsisp.com\/helps\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"\u524d\u7aef\u57fa\u7840\u2014\u2014JavaScript\uff08\u57fa\u7840\u8bed\u6cd5\uff09\uff08\u4e0a\u7bc7\uff09\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\/\/www.wsisp.com\/helps\/#website\",\"url\":\"https:\/\/www.wsisp.com\/helps\/\",\"name\":\"\u7f51\u7855\u4e92\u8054\u5e2e\u52a9\u4e2d\u5fc3\",\"description\":\"\u9999\u6e2f\u670d\u52a1\u5668_\u9999\u6e2f\u4e91\u670d\u52a1\u5668\u8d44\u8baf_\u670d\u52a1\u5668\u5e2e\u52a9\u6587\u6863_\u670d\u52a1\u5668\u6559\u7a0b\",\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\/\/www.wsisp.com\/helps\/?s={search_term_string}\"},\"query-input\":\"required name=search_term_string\"}],\"inLanguage\":\"zh-Hans\"},{\"@type\":\"Person\",\"@id\":\"https:\/\/www.wsisp.com\/helps\/#\/schema\/person\/358e386c577a3ab51c4493330a20ad41\",\"name\":\"admin\",\"image\":{\"@type\":\"ImageObject\",\"inLanguage\":\"zh-Hans\",\"@id\":\"https:\/\/www.wsisp.com\/helps\/#\/schema\/person\/image\/\",\"url\":\"https:\/\/gravatar.wp-china-yes.net\/avatar\/?s=96&d=mystery\",\"contentUrl\":\"https:\/\/gravatar.wp-china-yes.net\/avatar\/?s=96&d=mystery\",\"caption\":\"admin\"},\"sameAs\":[\"http:\/\/wp.wsisp.com\"],\"url\":\"https:\/\/www.wsisp.com\/helps\/author\/admin\"}]}<\/script>\n<!-- \/ Yoast SEO plugin. -->","yoast_head_json":{"title":"\u524d\u7aef\u57fa\u7840\u2014\u2014JavaScript\uff08\u57fa\u7840\u8bed\u6cd5\uff09\uff08\u4e0a\u7bc7\uff09 - \u7f51\u7855\u4e92\u8054\u5e2e\u52a9\u4e2d\u5fc3","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/www.wsisp.com\/helps\/100598.html","og_locale":"zh_CN","og_type":"article","og_title":"\u524d\u7aef\u57fa\u7840\u2014\u2014JavaScript\uff08\u57fa\u7840\u8bed\u6cd5\uff09\uff08\u4e0a\u7bc7\uff09 - \u7f51\u7855\u4e92\u8054\u5e2e\u52a9\u4e2d\u5fc3","og_description":"\u76ee\u5f55 \u521d\u8bc6JavaScript JavaScript\u662f\u4ec0\u4e48 \u53d1\u5c55\u5386\u53f2 JavaScript\u548cHTML\u548cCSS\u4e4b\u95f4\u7684\u5173\u7cfb JavaScript\u8fd0\u884c\u8fc7\u7a0b JavaScript\u7684\u7ec4\u6210 \u91cd\u8981\u6982\u5ff5: ECMAScript \u524d\u7f6e\u77e5\u8bc6 \u7b2c\u4e00\u4e2a\u7a0b\u5e8f JavaScript\u7684\u4e66\u5199\u5f62\u5f0f \u884c\u5185\u5f0f \u5185\u5d4c\u5f0f \u5916\u90e8\u5f0f \u6ce8\u91ca \u8f93\u5165\u8f93\u51fa \u8f93\u5165：prompt \u8f93\u51fa：alert \u8f93\u51fa：console.log \u91cd\u8981\u6982\u5ff5：\u65e5","og_url":"https:\/\/www.wsisp.com\/helps\/100598.html","og_site_name":"\u7f51\u7855\u4e92\u8054\u5e2e\u52a9\u4e2d\u5fc3","article_published_time":"2026-09-04T13:18:11+00:00","og_image":[{"url":"https:\/\/www.wsisp.com\/helps\/wp-content\/uploads\/2026\/09\/20260904131802-6a9ac50aa924f.png"}],"author":"admin","twitter_card":"summary_large_image","twitter_misc":{"\u4f5c\u8005":"admin","\u9884\u8ba1\u9605\u8bfb\u65f6\u95f4":"8 \u5206"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"WebPage","@id":"https:\/\/www.wsisp.com\/helps\/100598.html","url":"https:\/\/www.wsisp.com\/helps\/100598.html","name":"\u524d\u7aef\u57fa\u7840\u2014\u2014JavaScript\uff08\u57fa\u7840\u8bed\u6cd5\uff09\uff08\u4e0a\u7bc7\uff09 - \u7f51\u7855\u4e92\u8054\u5e2e\u52a9\u4e2d\u5fc3","isPartOf":{"@id":"https:\/\/www.wsisp.com\/helps\/#website"},"datePublished":"2026-09-04T13:18:11+00:00","dateModified":"2026-09-04T13:18:11+00:00","author":{"@id":"https:\/\/www.wsisp.com\/helps\/#\/schema\/person\/358e386c577a3ab51c4493330a20ad41"},"breadcrumb":{"@id":"https:\/\/www.wsisp.com\/helps\/100598.html#breadcrumb"},"inLanguage":"zh-Hans","potentialAction":[{"@type":"ReadAction","target":["https:\/\/www.wsisp.com\/helps\/100598.html"]}]},{"@type":"BreadcrumbList","@id":"https:\/\/www.wsisp.com\/helps\/100598.html#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"\u9996\u9875","item":"https:\/\/www.wsisp.com\/helps"},{"@type":"ListItem","position":2,"name":"\u524d\u7aef\u57fa\u7840\u2014\u2014JavaScript\uff08\u57fa\u7840\u8bed\u6cd5\uff09\uff08\u4e0a\u7bc7\uff09"}]},{"@type":"WebSite","@id":"https:\/\/www.wsisp.com\/helps\/#website","url":"https:\/\/www.wsisp.com\/helps\/","name":"\u7f51\u7855\u4e92\u8054\u5e2e\u52a9\u4e2d\u5fc3","description":"\u9999\u6e2f\u670d\u52a1\u5668_\u9999\u6e2f\u4e91\u670d\u52a1\u5668\u8d44\u8baf_\u670d\u52a1\u5668\u5e2e\u52a9\u6587\u6863_\u670d\u52a1\u5668\u6559\u7a0b","potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/www.wsisp.com\/helps\/?s={search_term_string}"},"query-input":"required name=search_term_string"}],"inLanguage":"zh-Hans"},{"@type":"Person","@id":"https:\/\/www.wsisp.com\/helps\/#\/schema\/person\/358e386c577a3ab51c4493330a20ad41","name":"admin","image":{"@type":"ImageObject","inLanguage":"zh-Hans","@id":"https:\/\/www.wsisp.com\/helps\/#\/schema\/person\/image\/","url":"https:\/\/gravatar.wp-china-yes.net\/avatar\/?s=96&d=mystery","contentUrl":"https:\/\/gravatar.wp-china-yes.net\/avatar\/?s=96&d=mystery","caption":"admin"},"sameAs":["http:\/\/wp.wsisp.com"],"url":"https:\/\/www.wsisp.com\/helps\/author\/admin"}]}},"_links":{"self":[{"href":"https:\/\/www.wsisp.com\/helps\/wp-json\/wp\/v2\/posts\/100598","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.wsisp.com\/helps\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.wsisp.com\/helps\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.wsisp.com\/helps\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.wsisp.com\/helps\/wp-json\/wp\/v2\/comments?post=100598"}],"version-history":[{"count":0,"href":"https:\/\/www.wsisp.com\/helps\/wp-json\/wp\/v2\/posts\/100598\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.wsisp.com\/helps\/wp-json\/wp\/v2\/media\/100578"}],"wp:attachment":[{"href":"https:\/\/www.wsisp.com\/helps\/wp-json\/wp\/v2\/media?parent=100598"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.wsisp.com\/helps\/wp-json\/wp\/v2\/categories?post=100598"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.wsisp.com\/helps\/wp-json\/wp\/v2\/tags?post=100598"},{"taxonomy":"topic","embeddable":true,"href":"https:\/\/www.wsisp.com\/helps\/wp-json\/wp\/v2\/topic?post=100598"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}