{"id":56358,"date":"2025-08-14T17:04:41","date_gmt":"2025-08-14T09:04:41","guid":{"rendered":"https:\/\/www.wsisp.com\/helps\/56358.html"},"modified":"2025-08-14T17:04:41","modified_gmt":"2025-08-14T09:04:41","slug":"javascript-reduce-%e6%96%b9%e6%b3%95%e8%af%a6%e8%a7%a3%e6%94%bb%e7%95%a5","status":"publish","type":"post","link":"https:\/\/www.wsisp.com\/helps\/56358.html","title":{"rendered":"JavaScript reduce \u65b9\u6cd5\u8be6\u89e3\u653b\u7565"},"content":{"rendered":"

\u524d\u8a00<\/h3>\n

reduce \u662f JavaScript \u6570\u7ec4\u539f\u578b\u5bf9\u8c61\u4e0a\u7684\u4e00\u4e2a\u5f3a\u5927\u65b9\u6cd5，\u5b83\u5141\u8bb8\u6211\u4eec\u5c06\u6570\u7ec4\u4e2d\u7684\u6240\u6709\u5143\u7d20\u6309\u7167\u6307\u5b9a\u7684\u903b\u8f91\u7d2f\u79ef\u8ba1\u7b97\u4e3a\u4e00\u4e2a\u5355\u4e00\u7684\u503c\u3002\u4f5c\u4e3a JavaScript \u5f00\u53d1\u8005\u5fc5\u987b\u638c\u63e1\u7684\u9ad8\u9636\u51fd\u6570\u4e4b\u4e00，reduce \u63d0\u4f9b\u4e86\u9ad8\u5ea6\u7684\u7075\u6d3b\u6027，\u53ef\u4ee5\u5b9e\u73b0\u4ece\u7b80\u5355\u7684\u6570\u7ec4\u6c42\u548c\u5230\u590d\u6742\u7684\u5bf9\u8c61\u7edf\u8ba1\u7b49\u591a\u79cd\u529f\u80fd\u3002\u672c\u653b\u7565\u5c06\u5168\u9762\u89e3\u6790 reduce \u65b9\u6cd5\u7684\u5b9a\u4e49\u3001\u53c2\u6570\u3001\u4f7f\u7528\u573a\u666f\u53ca\u5176\u5728\u5b9e\u9645\u5f00\u53d1\u4e2d\u7684\u5e94\u7528\u6280\u5de7\u3002<\/p>\n

reduce \u65b9\u6cd5\u7684\u57fa\u672c\u5b9a\u4e49\u4e0e\u8bed\u6cd5<\/h3>\n

\u5b98\u65b9\u5b9a\u4e49<\/h4>\n

reduce \u65b9\u6cd5\u5bf9\u6570\u7ec4\u4e2d\u7684\u6bcf\u4e2a\u5143\u7d20\u6267\u884c\u4e00\u4e2a\u7531\u60a8\u63d0\u4f9b\u7684 reducer \u51fd\u6570（\u5347\u5e8f\u6267\u884c），\u5c06\u5176\u7ed3\u679c\u6c47\u603b\u4e3a\u5355\u4e2a\u8fd4\u56de\u503c\u3002\u8be5\u65b9\u6cd5\u63a5\u6536\u4e00\u4e2a\u51fd\u6570\u4f5c\u4e3a\u7d2f\u52a0\u5668，\u6570\u7ec4\u4e2d\u7684\u6bcf\u4e2a\u503c（\u4ece\u5de6\u5230\u53f3）\u5f00\u59cb\u7f29\u51cf，\u6700\u7ec8\u8ba1\u7b97\u4e3a\u4e00\u4e2a\u503c[10]\u3002<\/p>\n

\u8bed\u6cd5\u7ed3\u6784<\/h4>\n

reduce \u65b9\u6cd5\u7684\u57fa\u672c\u8bed\u6cd5\u4e3a：<\/p>\n

arr.<\/span>reduce<\/span>(<\/span>callback,<\/span> initialValue)<\/span><\/p>\n

\u53c2\u6570\u8bf4\u660e<\/h4>\n

reduce \u65b9\u6cd5\u63a5\u53d7\u4e24\u4e2a\u53c2\u6570：<\/p>\n

  • callback：\u5fc5\u9700\u53c2\u6570，\u6267\u884c\u6570\u7ec4\u4e2d\u6bcf\u4e2a\u503c\u7684\u51fd\u6570（\u5982\u679c\u6ca1\u6709\u63d0\u4f9b initialValue，\u5219\u4ece\u6570\u7ec4\u7684\u7b2c\u4e8c\u4e2a\u5143\u7d20\u5f00\u59cb）<\/li>\n
  • initialValue：\u53ef\u9009\u53c2\u6570，\u7d2f\u52a0\u5668\u7684\u521d\u59cb\u503c<\/li>\n
    \u56de\u8c03\u51fd\u6570\u7684\u53c2\u6570<\/h5>\n

    \u4f20\u9012\u7ed9 reduce \u65b9\u6cd5\u7684\u56de\u8c03\u51fd\u6570\u5373callback\u5305\u542b\u56db\u4e2a\u53c2\u6570：<\/p>\n

      \n
    • accumulator（\u5fc5\u9700）：\u4e0a\u4e00\u6b21\u8c03\u7528\u56de\u8c03\u51fd\u6570\u8fd4\u56de\u7684\u503c，\u6216\u8005 initialValue（\u5982\u679c\u6307\u5b9a\u4e86\u521d\u59cb\u503c）<\/li>\n
    • currentValue（\u5fc5\u9700）：\u5f53\u524d\u5143\u7d20\u7684\u503c<\/li>\n
    • currentIndex（\u53ef\u9009）：\u5f53\u524d\u5143\u7d20\u5728\u6570\u7ec4\u4e2d\u7684\u7d22\u5f15<\/li>\n
    • array（\u53ef\u9009）：\u8c03\u7528 reduce \u7684\u6570\u7ec4[15]<\/li>\n<\/ul>\n

      \u6267\u884c\u8fc7\u7a0b<\/h4>\n

      reduce \u65b9\u6cd5\u7684\u6267\u884c\u8fc7\u7a0b\u5982\u4e0b：<\/p>\n

    • \u5982\u679c\u63d0\u4f9b\u4e86 initialValue，\u5219 accumulator \u4ece initialValue \u5f00\u59cb，\u904d\u5386\u4ece\u6570\u7ec4\u7684\u7b2c\u4e00\u4e2a\u5143\u7d20\u5f00\u59cb<\/li>\n
    • \u5982\u679c\u6ca1\u6709\u63d0\u4f9b initialValue，\u5219 accumulator \u4ece\u6570\u7ec4\u7684\u7b2c\u4e00\u4e2a\u5143\u7d20\u5f00\u59cb，\u904d\u5386\u4ece\u6570\u7ec4\u7684\u7b2c\u4e8c\u4e2a\u5143\u7d20\u5f00\u59cb<\/li>\n
    • \u56de\u8c03\u51fd\u6570\u5bf9\u6bcf\u4e2a\u5143\u7d20\u8fdb\u884c\u5904\u7406，\u8fd4\u56de\u7684\u7ed3\u679c\u4f5c\u4e3a\u4e0b\u4e00\u6b21\u8fed\u4ee3\u7684 accumulator \u53c2\u6570<\/li>\n
    • \u6700\u7ec8\u8fd4\u56de\u6700\u540e\u4e00\u6b21\u56de\u8c03\u51fd\u6570\u8c03\u7528\u7684\u7ed3\u679c[13]<\/li>\n

      reduce \u65b9\u6cd5\u7684\u4f7f\u7528\u573a\u666f\u4e0e\u793a\u4f8b<\/h3>\n

      \u6c42\u6570\u7ec4\u5143\u7d20\u603b\u548c<\/h4>\n

      \u6700\u5e38\u89c1\u7684\u4e00\u4e2a\u4f8b\u5b50\u662f\u4f7f\u7528 reduce \u6765\u8ba1\u7b97\u4e00\u4e2a\u6570\u503c\u6570\u7ec4\u4e2d\u6240\u6709\u6570\u7684\u603b\u548c：<\/p>\n

      const<\/span> numbers =<\/span> [<\/span>1<\/span>,<\/span> 2<\/span>,<\/span> 3<\/span>,<\/span> 4<\/span>,<\/span> 5<\/span>]<\/span>;<\/span>
      \nconst<\/span> sum =<\/span> numbers.<\/span>reduce<\/span>(<\/span>(<\/span>accumulator,<\/span> currentValue<\/span>)<\/span> =><\/span> accumulator +<\/span> currentValue,<\/span> 0<\/span>)<\/span>;<\/span>
      \nconsole.<\/span>log<\/span>(<\/span>sum)<\/span>;<\/span> \/\/ \u8f93\u51fa: 15<\/span><\/p>\n

      \u5728\u8fd9\u4e2a\u4f8b\u5b50\u4e2d，\u6211\u4eec\u63d0\u4f9b\u4e86\u4e00\u4e2a\u521d\u59cb\u503c 0，\u7136\u540e\u5c06\u6bcf\u4e2a\u5143\u7d20\u7684\u503c\u7d2f\u52a0\u5230 accumulator \u4e0a\u3002<\/p>\n

      \u6c42\u6570\u7ec4\u5143\u7d20\u7684\u5e73\u5747\u503c<\/h4>\n

      \u9664\u4e86\u6c42\u548c\u4e4b\u5916，reduce \u8fd8\u53ef\u4ee5\u4e0e\u6570\u7ec4\u7684\u957f\u5ea6\u5c5e\u6027\u7ed3\u5408\u4f7f\u7528，\u8ba1\u7b97\u6570\u7ec4\u5143\u7d20\u7684\u5e73\u5747\u503c：<\/p>\n

      const<\/span> numbers =<\/span> [<\/span>1<\/span>,<\/span> 2<\/span>,<\/span> 3<\/span>,<\/span> 4<\/span>,<\/span> 5<\/span>]<\/span>;<\/span>
      \nconst<\/span> sum =<\/span> numbers.<\/span>reduce<\/span>(<\/span>(<\/span>accumulator,<\/span> currentValue<\/span>)<\/span> =><\/span> accumulator +<\/span> currentValue,<\/span> 0<\/span>)<\/span>;<\/span>
      \nconst<\/span> average =<\/span> sum \/<\/span> numbers.<\/span>length;<\/span>
      \nconsole.<\/span>log<\/span>(<\/span>average)<\/span>;<\/span> \/\/ \u8f93\u51fa: 3<\/span><\/p>\n

      \u6c42\u6700\u5927\u503c\u6216\u6700\u5c0f\u503c<\/h4>\n

      reduce \u53ef\u4ee5\u7528\u6765\u627e\u51fa\u6570\u7ec4\u4e2d\u7684\u6700\u5927\u503c\u6216\u6700\u5c0f\u503c：<\/p>\n

      const<\/span> numbers =<\/span> [<\/span>4<\/span>,<\/span> 2<\/span>,<\/span> 7<\/span>]<\/span>;<\/span>
      \nconst<\/span> max =<\/span> numbers.<\/span>reduce<\/span>(<\/span>(<\/span>a,<\/span> b<\/span>)<\/span> =><\/span> Math.<\/span>max<\/span>(<\/span>a,<\/span> b)<\/span>,<\/span> –<\/span>Infinity<\/span>)<\/span>;<\/span> \/\/ 7<\/span>
      \nconst<\/span> min =<\/span> numbers.<\/span>reduce<\/span>(<\/span>(<\/span>a,<\/span> b<\/span>)<\/span> =><\/span> Math.<\/span>min<\/span>(<\/span>a,<\/span> b)<\/span>,<\/span> Infinity<\/span>)<\/span>;<\/span> \/\/ 2<\/span><\/p>\n

      \u5904\u7406\u5bf9\u8c61\u6570\u7ec4<\/h4>\n

      reduce \u53ef\u4ee5\u7528\u6765\u5904\u7406\u5bf9\u8c61\u6570\u7ec4，\u4f8b\u5982\u7d2f\u52a0\u5bf9\u8c61\u7684\u67d0\u4e2a\u5c5e\u6027：<\/p>\n

      const<\/span> arr =<\/span> [<\/span>{<\/span>x<\/span>:<\/span> 1<\/span>}<\/span>,<\/span> {<\/span>x<\/span>:<\/span> 2<\/span>}<\/span>,<\/span> {<\/span>x<\/span>:<\/span> 3<\/span>}<\/span>]<\/span>;<\/span>
      \nconst<\/span> sum =<\/span> arr.<\/span>reduce<\/span>(<\/span>(<\/span>acc,<\/span> obj<\/span>)<\/span> =><\/span> acc +<\/span> obj.<\/span>x,<\/span> 0<\/span>)<\/span>;<\/span>
      \nconsole.<\/span>log<\/span>(<\/span>sum)<\/span>;<\/span> \/\/ \u8f93\u51fa: 6<\/span><\/p>\n

      \u6570\u7ec4\u53bb\u91cd<\/h4>\n

      reduce \u53ef\u4ee5\u7528\u6765\u5b9e\u73b0\u6570\u7ec4\u53bb\u91cd\u7684\u529f\u80fd：<\/p>\n

      const<\/span> arr =<\/span> [<\/span>1<\/span>,<\/span> 2<\/span>,<\/span> 3<\/span>,<\/span> 3<\/span>,<\/span> 2<\/span>,<\/span> 1<\/span>,<\/span> 4<\/span>]<\/span>;<\/span>
      \nconst<\/span> uniqueArr =<\/span> arr.<\/span>reduce<\/span>(<\/span>(<\/span>acc,<\/span> cur<\/span>)<\/span> =><\/span> {<\/span>
      \n if<\/span> (<\/span>!<\/span>acc.<\/span>includes<\/span>(<\/span>cur)<\/span>)<\/span> {<\/span>
      \n acc.<\/span>push<\/span>(<\/span>cur)<\/span>;<\/span>
      \n }<\/span>
      \n return<\/span> acc;<\/span>
      \n}<\/span>,<\/span> [<\/span>]<\/span>)<\/span>;<\/span>
      \nconsole.<\/span>log<\/span>(<\/span>uniqueArr)<\/span>;<\/span> \/\/ \u8f93\u51fa: [1, 2, 3, 4]<\/span><\/p>\n

      \u5c06\u6570\u7ec4\u5143\u7d20\u8f6c\u6362\u4e3a\u5bf9\u8c61<\/h4>\n

      reduce \u53ef\u4ee5\u7528\u6765\u5c06\u6570\u7ec4\u5143\u7d20\u8f6c\u6362\u4e3a\u5bf9\u8c61\u7ed3\u6784：<\/p>\n

      const<\/span> users =<\/span> [<\/span>{<\/span>id<\/span>:<\/span> 1<\/span>,<\/span> name<\/span>:<\/span> 'Alice'<\/span>}<\/span>,<\/span> {<\/span>id<\/span>:<\/span> 2<\/span>,<\/span> name<\/span>:<\/span> 'Bob'<\/span>}<\/span>]<\/span>;<\/span>
      \nconst<\/span> userById =<\/span> users.<\/span>reduce<\/span>(<\/span>(<\/span>acc,<\/span> user<\/span>)<\/span> =><\/span> {<\/span>
      \n acc[<\/span>user.<\/span>id]<\/span> =<\/span> user;<\/span>
      \n return<\/span> acc;<\/span>
      \n}<\/span>,<\/span> {<\/span>}<\/span>)<\/span>;<\/span>
      \nconsole.<\/span>log<\/span>(<\/span>userById)<\/span>;<\/span> \/\/ \u8f93\u51fa: {1: {id: 1, name: 'Alice'}, 2: {id: 2, name: 'Bob'}}<\/span><\/p>\n

      \u6309\u5c5e\u6027\u5206\u7ec4<\/h4>\n

      reduce \u53ef\u4ee5\u7528\u6765\u6839\u636e\u5bf9\u8c61\u7684\u67d0\u4e2a\u5c5e\u6027\u5c06\u6570\u7ec4\u5143\u7d20\u5206\u7ec4：<\/p>\n

      const<\/span> arr =<\/span> [<\/span>
      \n {<\/span> name<\/span>:<\/span> 'apple'<\/span>,<\/span> type<\/span>:<\/span> 'fruit'<\/span>,<\/span> color<\/span>:<\/span> 'red'<\/span> }<\/span>,<\/span>
      \n {<\/span> name<\/span>:<\/span> 'banana'<\/span>,<\/span> type<\/span>:<\/span> 'fruit'<\/span>,<\/span> color<\/span>:<\/span> 'yellow'<\/span> }<\/span>,<\/span>
      \n {<\/span> name<\/span>:<\/span> 'carrot'<\/span>,<\/span> type<\/span>:<\/span> 'vegetable'<\/span>,<\/span> color<\/span>:<\/span> 'orange'<\/span> }<\/span>,<\/span>
      \n {<\/span> name<\/span>:<\/span> 'broccoli'<\/span>,<\/span> type<\/span>:<\/span> 'vegetable'<\/span>,<\/span> color<\/span>:<\/span> 'green'<\/span> }<\/span>,<\/span>
      \n]<\/span>;<\/span>
      \nconst<\/span> result =<\/span> arr.<\/span>reduce<\/span>(<\/span>(<\/span>acc,<\/span> cur<\/span>)<\/span> =><\/span> {<\/span>
      \n if<\/span> (<\/span>!<\/span>acc[<\/span>cur.<\/span>type]<\/span>)<\/span> {<\/span>
      \n acc[<\/span>cur.<\/span>type]<\/span> =<\/span> [<\/span>]<\/span>;<\/span>
      \n }<\/span>
      \n acc[<\/span>cur.<\/span>type]<\/span>.<\/span>push<\/span>(<\/span>cur)<\/span>;<\/span>
      \n return<\/span> acc;<\/span>
      \n}<\/span>,<\/span> {<\/span>}<\/span>)<\/span>;<\/span>
      \nconsole.<\/span>log<\/span>(<\/span>result)<\/span>;<\/span>
      \n\/\/ \u8f93\u51fa:<\/span>
      \n\/\/ {<\/span>
      \n\/\/ fruit: [{name: 'apple', type: 'fruit', color: 'red'}, {name: 'banana', type: 'fruit', color: 'yellow'}],<\/span>
      \n\/\/ vegetable: [{name: 'carrot', type: 'vegetable', color: 'orange'}, {name: 'broccoli', type: 'vegetable', color: 'green'}]<\/span>
      \n\/\/ }<\/span><\/p>\n

      \u5c55\u5f00\u591a\u7ef4\u6570\u7ec4<\/h4>\n

      reduce \u53ef\u4ee5\u7528\u6765\u5c06\u591a\u7ef4\u6570\u7ec4\u5c55\u5f00\u4e3a\u4e00\u7ef4\u6570\u7ec4：<\/p>\n

      const<\/span> arr =<\/span> [<\/span>1<\/span>,<\/span> [<\/span>2<\/span>,<\/span> 3<\/span>]<\/span>,<\/span> [<\/span>4<\/span>,<\/span> 5<\/span>]<\/span>,<\/span> 6<\/span>]<\/span>;<\/span>
      \nconst<\/span> flattened =<\/span> arr.<\/span>reduce<\/span>(<\/span>(<\/span>acc,<\/span> current<\/span>)<\/span> =><\/span> {<\/span>
      \n if<\/span> (<\/span>Array.<\/span>isArray<\/span>(<\/span>current)<\/span>)<\/span> {<\/span>
      \n return<\/span> acc.<\/span>concat<\/span>(<\/span>current)<\/span>;<\/span>
      \n }<\/span> else<\/span> {<\/span>
      \n acc.<\/span>push<\/span>(<\/span>current)<\/span>;<\/span>
      \n return<\/span> acc;<\/span>
      \n }<\/span>
      \n}<\/span>,<\/span> [<\/span>]<\/span>)<\/span>;<\/span>
      \nconsole.<\/span>log<\/span>(<\/span>flattened)<\/span>;<\/span> \/\/ \u8f93\u51fa: [1, 2, 3, 4, 5, 6]<\/span><\/p>\n

      reduce \u65b9\u6cd5\u7684\u9ad8\u7ea7\u7528\u6cd5<\/h3>\n

      \u590d\u6742\u903b\u8f91\u7d2f\u79ef<\/h4>\n

      reduce \u4e0d\u4ec5\u53ef\u4ee5\u7528\u4e8e\u7b80\u5355\u7684\u6c42\u548c，\u8fd8\u53ef\u4ee5\u5b9e\u73b0\u66f4\u590d\u6742\u7684\u903b\u8f91，\u5982\u8fc7\u6ee4\u3001\u6620\u5c04\u548c\u7d2f\u79ef\u7684\u7ec4\u5408：<\/p>\n

      const<\/span> arr =<\/span> [<\/span>1<\/span>,<\/span> 2<\/span>,<\/span> 3<\/span>,<\/span> 4<\/span>,<\/span> 5<\/span>]<\/span>;<\/span>
      \nconst<\/span> sumOfEven =<\/span> arr.<\/span>reduce<\/span>(<\/span>(<\/span>acc,<\/span> cur<\/span>)<\/span> =><\/span> {<\/span>
      \n if<\/span> (<\/span>cur %<\/span> 2<\/span> ===<\/span> 0<\/span>)<\/span> {<\/span>
      \n return<\/span> acc +<\/span> cur;<\/span>
      \n }<\/span>
      \n return<\/span> acc;<\/span>
      \n}<\/span>,<\/span> 0<\/span>)<\/span>;<\/span>
      \nconsole.<\/span>log<\/span>(<\/span>sumOfEven)<\/span>;<\/span> \/\/ \u8f93\u51fa: 2 + 4 = 6<\/span><\/p>\n

      \u4e0e map \u7ed3\u5408\u4f7f\u7528<\/h4>\n

      \u901a\u8fc7 reduce \u53ef\u4ee5\u5b9e\u73b0\u7c7b\u4f3c\u4e8e map \u7684\u529f\u80fd：<\/p>\n

      Array<\/span>.<\/span>prototype.<\/span>myMap<\/span> =<\/span> function<\/span> (<\/span>fn<\/span>)<\/span> {<\/span>
      \n return<\/span> this<\/span>.<\/span>reduce<\/span>(<\/span>(<\/span>pre,<\/span> cur,<\/span> index,<\/span> arr<\/span>)<\/span> =><\/span> {<\/span>
      \n pre.<\/span>push<\/span>(<\/span>fn<\/span>(<\/span>cur,<\/span> index,<\/span> arr)<\/span>)<\/span>;<\/span>
      \n return<\/span> pre;<\/span>
      \n }<\/span>,<\/span> [<\/span>]<\/span>)<\/span>;<\/span>
      \n}<\/span>;<\/span>
      \nconst<\/span> numbers =<\/span> [<\/span>1<\/span>,<\/span> 2<\/span>,<\/span> 3<\/span>]<\/span>;<\/span>
      \nconst<\/span> mapped =<\/span> numbers.<\/span>myMap<\/span>(<\/span>x<\/span> =><\/span> x *<\/span> 2<\/span>)<\/span>;<\/span>
      \nconsole.<\/span>log<\/span>(<\/span>mapped)<\/span>;<\/span> \/\/ \u8f93\u51fa: [2, 4, 6]<\/span><\/p>\n

      \u5b9e\u73b0\u7ba1\u9053\u51fd\u6570<\/h4>\n

      reduce \u53ef\u4ee5\u7528\u6765\u5b9e\u73b0\u51fd\u6570\u7ba1\u9053，\u6309\u7167\u7279\u5b9a\u987a\u5e8f\u6267\u884c\u4e00\u7cfb\u5217\u51fd\u6570：<\/p>\n

      const<\/span> pipeline<\/span> =<\/span> (<\/span>value,<\/span> functions<\/span>)<\/span> =><\/span> {<\/span>
      \n return<\/span> functions.<\/span>reduce<\/span>(<\/span>(<\/span>acc,<\/span> func<\/span>)<\/span> =><\/span> {<\/span>
      \n return<\/span> func<\/span>(<\/span>acc)<\/span>;<\/span>
      \n }<\/span>,<\/span> value)<\/span>;<\/span>
      \n}<\/span>;<\/span>
      \nconst<\/span> functions =<\/span> [<\/span>
      \n x<\/span> =><\/span> x +<\/span> 2<\/span>,<\/span>
      \n x<\/span> =><\/span> x *<\/span> 3<\/span>,<\/span>
      \n x<\/span> =><\/span> x.<\/span>toString<\/span>(<\/span>)<\/span>
      \n]<\/span>;<\/span>
      \nconsole.<\/span>log<\/span>(<\/span>pipeline<\/span>(<\/span>4<\/span>,<\/span> functions)<\/span>)<\/span>;<\/span> \/\/ \u8f93\u51fa: "18"<\/span><\/p>\n

      reduce \u65b9\u6cd5\u7684\u6ce8\u610f\u4e8b\u9879\u4e0e\u6700\u4f73\u5b9e\u8df5<\/h3>\n

      \u521d\u59cb\u503c\u7684\u91cd\u8981\u6027<\/h4>\n

      \u5982\u679c\u6570\u7ec4\u4e3a\u7a7a\u4e14\u6ca1\u6709\u63d0\u4f9b\u521d\u59cb\u503c，reduce \u4f1a\u8fd4\u56de undefined，\u800c\u4e0d\u662f\u629b\u51fa\u9519\u8bef\u3002\u56e0\u6b64，\u5728\u5904\u7406\u53ef\u80fd\u4e3a\u7a7a\u7684\u6570\u7ec4\u65f6，\u5efa\u8bae\u63d0\u4f9b\u4e00\u4e2a\u5408\u7406\u7684\u521d\u59cb\u503c：<\/p>\n

      const<\/span> emptyArray =<\/span> [<\/span>]<\/span>;<\/span>
      \nconst<\/span> sum =<\/span> emptyArray.<\/span>reduce<\/span>(<\/span>(<\/span>acc,<\/span> cur<\/span>)<\/span> =><\/span> acc +<\/span> cur,<\/span> 0<\/span>)<\/span>;<\/span> \/\/ 0<\/span>
      \n\/\/ \u5982\u679c\u4e0d\u63d0\u4f9b\u521d\u59cb\u503c：<\/span>
      \nconst<\/span> sumWithoutInitial =<\/span> emptyArray.<\/span>reduce<\/span>(<\/span>(<\/span>acc,<\/span> cur<\/span>)<\/span> =><\/span> acc +<\/span> cur)<\/span>;<\/span> \/\/ undefined<\/span><\/p>\n

      \u5904\u7406\u5bf9\u8c61\u6570\u7ec4\u65f6\u7684\u6df1\u62f7\u8d1d\u95ee\u9898<\/h4>\n

      \u5f53\u5728 reduce \u4e2d\u64cd\u4f5c\u5bf9\u8c61\u65f6，\u9700\u8981\u786e\u4fdd\u5bf9\u5bf9\u8c61\u8fdb\u884c\u6df1\u62f7\u8d1d，\u907f\u514d\u4fee\u6539\u539f\u59cb\u5bf9\u8c61：<\/p>\n

      const<\/span> arr =<\/span> [<\/span>{<\/span>x<\/span>:<\/span> 1<\/span>}<\/span>]<\/span>;<\/span>
      \nconst<\/span> mapped =<\/span> arr.<\/span>reduce<\/span>(<\/span>(<\/span>acc,<\/span> obj<\/span>)<\/span> =><\/span> {<\/span>
      \n const<\/span> newObj =<\/span> {<\/span>…<\/span>obj}<\/span>;<\/span> \/\/ \u6df1\u62f7\u8d1d<\/span>
      \n newObj.<\/span>x +=<\/span> 1<\/span>;<\/span>
      \n acc.<\/span>push<\/span>(<\/span>newObj)<\/span>;<\/span>
      \n return<\/span> acc;<\/span>
      \n}<\/span>,<\/span> [<\/span>]<\/span>)<\/span>;<\/span>
      \nconsole.<\/span>log<\/span>(<\/span>arr)<\/span>;<\/span> \/\/ \u539f\u59cb\u6570\u7ec4\u4fdd\u6301\u4e0d\u53d8：[{x: 1}]<\/span>
      \nconsole.<\/span>log<\/span>(<\/span>mapped)<\/span>;<\/span> \/\/ \u65b0\u6570\u7ec4：[{x: 2}]<\/span><\/p>\n

      \u6ce8\u610f\u7d22\u5f15\u7684\u8d77\u59cb\u4f4d\u7f6e<\/h4>\n

      \u5f53\u63d0\u4f9b\u521d\u59cb\u503c\u65f6，reduce \u4f1a\u4ece\u6570\u7ec4\u7684\u7b2c\u4e00\u4e2a\u5143\u7d20（\u7d22\u5f15 0）\u5f00\u59cb\u5904\u7406；\u5f53\u4e0d\u63d0\u4f9b\u521d\u59cb\u503c\u65f6，reduce \u4f1a\u4ece\u6570\u7ec4\u7684\u7b2c\u4e8c\u4e2a\u5143\u7d20（\u7d22\u5f15 1）\u5f00\u59cb\u5904\u7406：<\/p>\n

      const<\/span> arr =<\/span> [<\/span>1<\/span>,<\/span> 2<\/span>,<\/span> 3<\/span>]<\/span>;<\/span>
      \nconst<\/span> withInitial =<\/span> arr.<\/span>reduce<\/span>(<\/span>(<\/span>acc,<\/span> cur,<\/span> index<\/span>)<\/span> =><\/span> {<\/span>
      \n console.<\/span>log<\/span>(<\/span>index)<\/span>;<\/span> \/\/ 0, 1, 2<\/span>
      \n return<\/span> acc +<\/span> cur;<\/span>
      \n}<\/span>,<\/span> 0<\/span>)<\/span>;<\/span>
      \nconst<\/span> withoutInitial =<\/span> arr.<\/span>reduce<\/span>(<\/span>(<\/span>acc,<\/span> cur,<\/span> index<\/span>)<\/span> =><\/span> {<\/span>
      \n console.<\/span>log<\/span>(<\/span>index)<\/span>;<\/span> \/\/ 1, 2<\/span>
      \n return<\/span> acc +<\/span> cur;<\/span>
      \n}<\/span>)<\/span>;<\/span><\/p>\n

      \u907f\u514d\u4e0d\u5fc5\u8981\u7684\u53c2\u6570<\/h4>\n

      \u5982\u679c\u4e0d\u9700\u8981\u4f7f\u7528 index \u548c array \u53c2\u6570，\u53ef\u4ee5\u53ea\u4f7f\u7528 accumulator \u548c currentValue \u4e24\u4e2a\u53c2\u6570，\u4f7f\u4ee3\u7801\u66f4\u7b80\u6d01：<\/p>\n

      const<\/span> numbers =<\/span> [<\/span>1<\/span>,<\/span> 2<\/span>,<\/span> 3<\/span>]<\/span>;<\/span>
      \nconst<\/span> sum =<\/span> numbers.<\/span>reduce<\/span>(<\/span>(<\/span>acc,<\/span> cur<\/span>)<\/span> =><\/span> acc +<\/span> cur,<\/span> 0<\/span>)<\/span>;<\/span> \/\/ \u66f4\u7b80\u6d01<\/span>
      \nconst<\/span> sumWithAllParams =<\/span> numbers.<\/span>reduce<\/span>(<\/span>(<\/span>acc,<\/span> cur,<\/span> index,<\/span> arr<\/span>)<\/span> =><\/span> acc +<\/span> cur,<\/span> 0<\/span>)<\/span>;<\/span> \/\/ \u5305\u542b\u6240\u6709\u53c2\u6570<\/span><\/p>\n

      reduce \u4e0e\u5176\u5b83\u6570\u7ec4\u65b9\u6cd5\u7684\u5bf9\u6bd4<\/h3>\n

      reduce \u4e0e for \u5faa\u73af<\/h4>\n

      \u867d\u7136 reduce \u53ef\u4ee5\u5b9e\u73b0 for \u5faa\u73af\u7684\u529f\u80fd，\u4f46 reduce \u63d0\u4f9b\u4e86\u66f4\u58f0\u660e\u5f0f\u7684\u5199\u6cd5，\u4f7f\u4ee3\u7801\u66f4\u6613\u8bfb：<\/p>\n

      const<\/span> numbers =<\/span> [<\/span>1<\/span>,<\/span> 2<\/span>,<\/span> 3<\/span>]<\/span>;<\/span>
      \nlet<\/span> sum =<\/span> 0<\/span>;<\/span>
      \nfor<\/span> (<\/span>let<\/span> i =<\/span> 0<\/span>;<\/span> i <<\/span> numbers.<\/span>length;<\/span> i++<\/span>)<\/span> {<\/span>
      \n sum +=<\/span> numbers[<\/span>i]<\/span>;<\/span>
      \n}<\/span>
      \nconsole.<\/span>log<\/span>(<\/span>sum)<\/span>;<\/span> \/\/ 6<\/span>
      \nconst<\/span> sumWithReduce =<\/span> numbers.<\/span>reduce<\/span>(<\/span>(<\/span>acc,<\/span> cur<\/span>)<\/span> =><\/span> acc +<\/span> cur,<\/span> 0<\/span>)<\/span>;<\/span>
      \nconsole.<\/span>log<\/span>(<\/span>sumWithReduce)<\/span>;<\/span> \/\/ 6<\/span><\/p>\n

      reduce \u4e0e map\u3001filter<\/h4>\n

      reduce \u53ef\u4ee5\u4e0e map \u548c filter \u7ec4\u5408\u4f7f\u7528，\u5b9e\u73b0\u66f4\u590d\u6742\u7684\u529f\u80fd：<\/p>\n

      const<\/span> numbers =<\/span> [<\/span>1<\/span>,<\/span> 2<\/span>,<\/span> 3<\/span>,<\/span> 4<\/span>,<\/span> 5<\/span>]<\/span>;<\/span>
      \n\/\/ \u6c42\u5076\u6570\u7684\u5e73\u65b9\u548c<\/span>
      \nconst<\/span> sumOfEvenSquares =<\/span> numbers
      \n .<\/span>filter<\/span>(<\/span>x<\/span> =><\/span> x %<\/span> 2<\/span> ===<\/span> 0<\/span>)<\/span> \/\/ \u8fc7\u6ee4\u5076\u6570<\/span>
      \n .<\/span>map<\/span>(<\/span>x<\/span> =><\/span> x *<\/span> x)<\/span> \/\/ \u5e73\u65b9<\/span>
      \n .<\/span>reduce<\/span>(<\/span>(<\/span>acc,<\/span> cur<\/span>)<\/span> =><\/span> acc +<\/span> cur,<\/span> 0<\/span>)<\/span>;<\/span> \/\/ \u6c42\u548c<\/span>
      \nconsole.<\/span>log<\/span>(<\/span>sumOfEvenSquares)<\/span>;<\/span> \/\/ 2^2 + 4^2 = 4 + 16 = 20<\/span><\/p>\n

      reduce \u4e0e reduceRight<\/h4>\n

      reduceRight \u4e0e reduce \u7c7b\u4f3c，\u4f46\u5904\u7406\u6570\u7ec4\u7684\u65b9\u5411\u662f\u4ece\u53f3\u5230\u5de6（\u4ece\u6700\u540e\u4e00\u4e2a\u5143\u7d20\u5f00\u59cb）：<\/p>\n

      const<\/span> arr =<\/span> [<\/span>1<\/span>,<\/span> 2<\/span>,<\/span> 3<\/span>,<\/span> 4<\/span>]<\/span>;<\/span>
      \nconst<\/span> sumWithReduce =<\/span> arr.<\/span>reduce<\/span>(<\/span>(<\/span>acc,<\/span> cur<\/span>)<\/span> =><\/span> acc +<\/span> cur,<\/span> 0<\/span>)<\/span>;<\/span> \/\/ 1+2+3+4 = 10<\/span>
      \nconst<\/span> sumWithReduceRight =<\/span> arr.<\/span>reduceRight<\/span>(<\/span>(<\/span>acc,<\/span> cur<\/span>)<\/span> =><\/span> acc +<\/span> cur,<\/span> 0<\/span>)<\/span>;<\/span> \/\/ 4+3+2+1 = 10<\/span><\/p>\n

      \u603b\u7ed3<\/h3>\n

      reduce \u662f JavaScript \u6570\u7ec4\u539f\u578b\u4e0a\u7684\u4e00\u4e2a\u5f3a\u5927\u65b9\u6cd5，\u5b83\u5141\u8bb8\u6211\u4eec\u5c06\u6570\u7ec4\u5143\u7d20\u6309\u7167\u81ea\u5b9a\u4e49\u7684\u903b\u8f91\u7d2f\u79ef\u4e3a\u4e00\u4e2a\u5355\u4e00\u7684\u503c\u3002\u901a\u8fc7\u672c\u6587\u7684\u8be6\u7ec6\u89e3\u6790，\u6211\u4eec\u4e86\u89e3\u4e86 reduce \u65b9\u6cd5\u7684\u57fa\u672c\u8bed\u6cd5\u3001\u53c2\u6570\u8bf4\u660e\u3001\u5e38\u89c1\u4f7f\u7528\u573a\u666f\u4ee5\u53ca\u9ad8\u7ea7\u7528\u6cd5\u3002 \u4ece\u7b80\u5355\u7684\u6570\u7ec4\u6c42\u548c\u5230\u590d\u6742\u7684\u5bf9\u8c61\u7edf\u8ba1，reduce \u63d0\u4f9b\u4e86\u9ad8\u5ea6\u7684\u7075\u6d3b\u6027，\u80fd\u591f\u6ee1\u8db3\u5404\u79cd\u6570\u636e\u5904\u7406\u9700\u6c42\u3002\u901a\u8fc7\u4e0e\u5176\u4ed6\u6570\u7ec4\u65b9\u6cd5\u7684\u7ec4\u5408\u4f7f\u7528，\u6211\u4eec\u53ef\u4ee5\u5b9e\u73b0\u66f4\u590d\u6742\u7684\u529f\u80fd，\u5982\u8fc7\u6ee4\u3001\u6620\u5c04\u548c\u7edf\u8ba1\u7b49\u3002 \u5728\u4f7f\u7528 reduce \u65f6，\u9700\u8981\u6ce8\u610f\u521d\u59cb\u503c\u7684\u63d0\u4f9b\u3001\u5bf9\u8c61\u64cd\u4f5c\u65f6\u7684\u6df1\u62f7\u8d1d\u95ee\u9898\u4ee5\u53ca\u53c2\u6570\u7d22\u5f15\u7684\u8d77\u59cb\u4f4d\u7f6e\u7b49\u7ec6\u8282\u3002\u901a\u8fc7\u5408\u7406\u4f7f\u7528 reduce，\u6211\u4eec\u53ef\u4ee5\u7f16\u5199\u51fa\u66f4\u7b80\u6d01\u3001\u66f4\u6613\u8bfb\u7684\u4ee3\u7801，\u63d0\u9ad8\u5f00\u53d1\u6548\u7387\u3002 \u5e0c\u671b\u8fd9\u7bc7\u8be6\u89e3\u653b\u7565\u80fd\u591f\u5e2e\u52a9\u4f60\u5168\u9762\u4e86\u89e3 reduce \u65b9\u6cd5，\u638c\u63e1\u5176\u5728\u5b9e\u9645\u5f00\u53d1\u4e2d\u7684\u5e94\u7528\u6280\u5de7，\u63d0\u5347\u4f60\u7684 JavaScript \u7f16\u7a0b\u80fd\u529b\u3002<\/p>\n

      \u53c2\u8003\u8d44\u6599<\/h3>\n

      \u53c2\u8003\u8d44\u6599<\/h3>\n
    • MSDN: JavaScript reduce() \u65b9\u6cd5. http:\/\/msdn.microsoft.com\/en-us\/library\/ff679975(v=VS.94).aspx<\/li>\n
    • JavaScript\u4e2d\u7684reduce\u65b9\u6cd5\u6267\u884c\u8fc7\u7a0b\u3001\u4f7f\u7528\u573a\u666f\u53ca\u8fdb\u9636\u7528\u6cd5_javascript\u6280\u5de7_\u811a\u672c\u4e4b\u5bb6. https:\/\/www.jb51.net\/javascript\/33626426f.htm<\/li>\n
    • JS \u4e2dreduce()\u65b9\u6cd5\u53ca\u4f7f\u7528\u8be6\u89e3 – smil\u3001\u68b5\u97f3 – \u535a\u5ba2\u56ed. https:\/\/www.cnblogs.com\/smile-fanyin\/p\/18143685<\/li>\n
    • \u4f7f\u7528reduce\u65b9\u6cd5\u7684Javascript\u5206\u7ec4\u51fd\u6570 – \u817e\u8baf\u4e91\u5f00\u53d1\u8005. https:\/\/cloud.tencent.com\/developer\/information\/%E4%BD%BF%E7%94%A8reduce%E6%96%B9%E6%B3%95%E7%9A%84Javascript%E5%88%86%E7%BB%84%E5%87%BD%E6%95%B0-album<\/li>\n
    • JavaScript\u4e2darray.reduce()\u6570\u7ec4\u65b9\u6cd5\u7684\u56db\u79cd\u4f7f\u7528\u5b9e\u4f8b – \u535a\u5ba2\u56ed. https:\/\/www.cnblogs.com\/2008nmj\/p\/17510604.html<\/li>\n
    • javascript\u6570\u7ec4reduce\u9ad8\u7ea7\u7528\u6cd5\u6709\u54ea\u4e9b – \u4ebf\u901f\u4e91. https:\/\/www.yisu.com\/jc\/606796.html<\/li>\n
    • array_reduce – \u767e\u5ea6\u767e\u79d1. https:\/\/baike.baidu.com\/item\/array_reduce\/9040907<\/li>\n","protected":false},"excerpt":{"rendered":"

      \u6587\u7ae0\u6d4f\u89c8\u9605\u8bfb430\u6b21\uff0c\u70b9\u8d5e12\u6b21\uff0c\u6536\u85cf19\u6b21\u3002JavaScript \u7684 reduce \u65b9\u6cd5\u662f\u6570\u7ec4\u5904\u7406\u4e2d\u7684\u5f3a\u5927\u5de5\u5177\uff0c\u80fd\u591f\u5c06\u6570\u7ec4\u5143\u7d20\u7d2f\u79ef\u8ba1\u7b97\u4e3a\u5355\u4e00\u503c\u3002\u5176\u57fa\u672c\u8bed\u6cd5\u4e3a arr.reduce(callback, initialValue)\uff0c\u901a\u8fc7\u56de\u8c03\u51fd\u6570\u5b9e\u73b0\u7d2f\u52a0\u903b\u8f91\u3002\u5e38\u89c1\u5e94\u7528\u573a\u666f\u5305\u62ec\u6570\u7ec4\u6c42\u548c\u3001\u6c42\u5e73\u5747\u503c\u3001\u627e\u6781\u503c\u3001\u5bf9\u8c61\u6570\u7ec4\u5904\u7406\u3001\u6570\u7ec4\u53bb\u91cd\u548c\u5206\u7ec4\u7b49\u9ad8\u7ea7\u64cd\u4f5c\u3002\u4f7f\u7528 reduce \u65f6\u9700\u6ce8\u610f\u521d\u59cb\u503c\u7684\u8bbe\u7f6e\uff0c\u907f\u514d\u7a7a\u6570\u7ec4\u8fd4\u56de undefined\uff0c\u540c\u65f6\u6ce8\u610f\u5bf9\u8c61\u64cd\u4f5c\u7684\u6df1\u62f7\u8d1d\u95ee\u9898\u3002\u8be5\u65b9\u6cd5\u7075\u6d3b\u9ad8\u6548\uff0c\u80fd\u5b9e\u73b0 map\u3001filter \u7b49\u529f\u80fd\u7684\u7ec4\u5408\uff0c\u662f\u5f00\u53d1\u8005\u5fc5\u987b\u638c\u63e1\u7684\u9ad8\u9636\u51fd\u6570\u4e4b\u4e00\u3002<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[187],"topic":[],"class_list":["post-56358","post","type-post","status-publish","format-standard","hentry","category-server","tag-javascript"],"yoast_head":"\nJavaScript reduce \u65b9\u6cd5\u8be6\u89e3\u653b\u7565 - \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\/56358.html\" \/>\n<meta property=\"og:locale\" content=\"zh_CN\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"JavaScript reduce \u65b9\u6cd5\u8be6\u89e3\u653b\u7565 - \u7f51\u7855\u4e92\u8054\u5e2e\u52a9\u4e2d\u5fc3\" \/>\n<meta property=\"og:description\" content=\"\u6587\u7ae0\u6d4f\u89c8\u9605\u8bfb430\u6b21\uff0c\u70b9\u8d5e12\u6b21\uff0c\u6536\u85cf19\u6b21\u3002JavaScript \u7684 reduce \u65b9\u6cd5\u662f\u6570\u7ec4\u5904\u7406\u4e2d\u7684\u5f3a\u5927\u5de5\u5177\uff0c\u80fd\u591f\u5c06\u6570\u7ec4\u5143\u7d20\u7d2f\u79ef\u8ba1\u7b97\u4e3a\u5355\u4e00\u503c\u3002\u5176\u57fa\u672c\u8bed\u6cd5\u4e3a arr.reduce(callback, initialValue)\uff0c\u901a\u8fc7\u56de\u8c03\u51fd\u6570\u5b9e\u73b0\u7d2f\u52a0\u903b\u8f91\u3002\u5e38\u89c1\u5e94\u7528\u573a\u666f\u5305\u62ec\u6570\u7ec4\u6c42\u548c\u3001\u6c42\u5e73\u5747\u503c\u3001\u627e\u6781\u503c\u3001\u5bf9\u8c61\u6570\u7ec4\u5904\u7406\u3001\u6570\u7ec4\u53bb\u91cd\u548c\u5206\u7ec4\u7b49\u9ad8\u7ea7\u64cd\u4f5c\u3002\u4f7f\u7528 reduce \u65f6\u9700\u6ce8\u610f\u521d\u59cb\u503c\u7684\u8bbe\u7f6e\uff0c\u907f\u514d\u7a7a\u6570\u7ec4\u8fd4\u56de undefined\uff0c\u540c\u65f6\u6ce8\u610f\u5bf9\u8c61\u64cd\u4f5c\u7684\u6df1\u62f7\u8d1d\u95ee\u9898\u3002\u8be5\u65b9\u6cd5\u7075\u6d3b\u9ad8\u6548\uff0c\u80fd\u5b9e\u73b0 map\u3001filter \u7b49\u529f\u80fd\u7684\u7ec4\u5408\uff0c\u662f\u5f00\u53d1\u8005\u5fc5\u987b\u638c\u63e1\u7684\u9ad8\u9636\u51fd\u6570\u4e4b\u4e00\u3002\" \/>\n<meta property=\"og:url\" content=\"https:\/\/www.wsisp.com\/helps\/56358.html\" \/>\n<meta property=\"og:site_name\" content=\"\u7f51\u7855\u4e92\u8054\u5e2e\u52a9\u4e2d\u5fc3\" \/>\n<meta property=\"article:published_time\" content=\"2025-08-14T09:04:41+00:00\" \/>\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=\"4 \u5206\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\/\/schema.org\",\"@graph\":[{\"@type\":\"WebPage\",\"@id\":\"https:\/\/www.wsisp.com\/helps\/56358.html\",\"url\":\"https:\/\/www.wsisp.com\/helps\/56358.html\",\"name\":\"JavaScript reduce \u65b9\u6cd5\u8be6\u89e3\u653b\u7565 - 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\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\/56358.html","og_locale":"zh_CN","og_type":"article","og_title":"JavaScript reduce \u65b9\u6cd5\u8be6\u89e3\u653b\u7565 - \u7f51\u7855\u4e92\u8054\u5e2e\u52a9\u4e2d\u5fc3","og_description":"\u6587\u7ae0\u6d4f\u89c8\u9605\u8bfb430\u6b21\uff0c\u70b9\u8d5e12\u6b21\uff0c\u6536\u85cf19\u6b21\u3002JavaScript \u7684 reduce \u65b9\u6cd5\u662f\u6570\u7ec4\u5904\u7406\u4e2d\u7684\u5f3a\u5927\u5de5\u5177\uff0c\u80fd\u591f\u5c06\u6570\u7ec4\u5143\u7d20\u7d2f\u79ef\u8ba1\u7b97\u4e3a\u5355\u4e00\u503c\u3002\u5176\u57fa\u672c\u8bed\u6cd5\u4e3a arr.reduce(callback, initialValue)\uff0c\u901a\u8fc7\u56de\u8c03\u51fd\u6570\u5b9e\u73b0\u7d2f\u52a0\u903b\u8f91\u3002\u5e38\u89c1\u5e94\u7528\u573a\u666f\u5305\u62ec\u6570\u7ec4\u6c42\u548c\u3001\u6c42\u5e73\u5747\u503c\u3001\u627e\u6781\u503c\u3001\u5bf9\u8c61\u6570\u7ec4\u5904\u7406\u3001\u6570\u7ec4\u53bb\u91cd\u548c\u5206\u7ec4\u7b49\u9ad8\u7ea7\u64cd\u4f5c\u3002\u4f7f\u7528 reduce \u65f6\u9700\u6ce8\u610f\u521d\u59cb\u503c\u7684\u8bbe\u7f6e\uff0c\u907f\u514d\u7a7a\u6570\u7ec4\u8fd4\u56de undefined\uff0c\u540c\u65f6\u6ce8\u610f\u5bf9\u8c61\u64cd\u4f5c\u7684\u6df1\u62f7\u8d1d\u95ee\u9898\u3002\u8be5\u65b9\u6cd5\u7075\u6d3b\u9ad8\u6548\uff0c\u80fd\u5b9e\u73b0 map\u3001filter \u7b49\u529f\u80fd\u7684\u7ec4\u5408\uff0c\u662f\u5f00\u53d1\u8005\u5fc5\u987b\u638c\u63e1\u7684\u9ad8\u9636\u51fd\u6570\u4e4b\u4e00\u3002","og_url":"https:\/\/www.wsisp.com\/helps\/56358.html","og_site_name":"\u7f51\u7855\u4e92\u8054\u5e2e\u52a9\u4e2d\u5fc3","article_published_time":"2025-08-14T09:04:41+00:00","author":"admin","twitter_card":"summary_large_image","twitter_misc":{"\u4f5c\u8005":"admin","\u9884\u8ba1\u9605\u8bfb\u65f6\u95f4":"4 \u5206"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"WebPage","@id":"https:\/\/www.wsisp.com\/helps\/56358.html","url":"https:\/\/www.wsisp.com\/helps\/56358.html","name":"JavaScript reduce \u65b9\u6cd5\u8be6\u89e3\u653b\u7565 - 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