strlen \u7528\u4e8e\u8ba1\u7b97\u5b57\u7b26\u4e32\u7684\u6709\u6548\u957f\u5ea6（\u4e0d\u5305\u542b\u5b57\u7b26\u4e32\u7ec8\u6b62\u7b26 '\\\\0'），\u533a\u522b\u4e8e sizeof（\u8ba1\u7b97\u5185\u5b58\u5927\u5c0f）\u3002<\/p>\n
c<\/p>\n
\u8fd0\u884c<\/p>\n
#include <stdio.h>
\n#include <string.h><\/p>\n
int main() {
\n char str[] = "Hello World";
\n \/\/ \u8f93\u51fa 11（H\u5230d\u517111\u4e2a\u5b57\u7b26，\u4e0d\u542b'\\\\0'）
\n printf("\u5b57\u7b26\u4e32\u957f\u5ea6：%zu\\\\n", strlen(str));
\n \/\/ \u8f93\u51fa 12（\u5305\u542b'\\\\0'\u7684\u5185\u5b58\u5927\u5c0f）
\n printf("\u5185\u5b58\u5927\u5c0f：%zu\\\\n", sizeof(str));
\n return 0;
\n}<\/p>\n
c<\/p>\n
\u8fd0\u884c<\/p>\n
#include <stdio.h>
\n#include <assert.h> \/\/ \u7528\u4e8e\u7a7a\u6307\u9488\u68c0\u67e5<\/p>\n
\/\/ \u624b\u52a8\u5b9e\u73b0strlen：\u6307\u9488\u904d\u5386\u6cd5
\nsize_t my_strlen(const char *str) {
\n assert(str != NULL); \/\/ \u9632\u6b62\u4f20\u5165\u7a7a\u6307\u9488\u5bfc\u81f4\u5d29\u6e83
\n const char *p = str; \/\/ \u5b9a\u4e49\u6307\u9488\u6307\u5411\u5b57\u7b26\u4e32\u8d77\u59cb\u4f4d\u7f6e
\n \/\/ \u904d\u5386\u76f4\u5230\u9047\u5230'\\\\0'（\u5b57\u7b26\u4e32\u7ed3\u675f\u6807\u5fd7）
\n while (*p != '\\\\0') {
\n p++;
\n }
\n \/\/ \u6307\u9488\u5dee\u503c\u5373\u4e3a\u5b57\u7b26\u4e32\u957f\u5ea6
\n return p – str;
\n}<\/p>\n
\/\/ \u6d4b\u8bd5\u4ee3\u7801
\nint main() {
\n char str1[] = "C Language";
\n char str2[] = ""; \/\/ \u7a7a\u5b57\u7b26\u4e32
\n \/\/ \u8f93\u51fa 10
\n printf("my_strlen(\\\\"C Language\\\\") = %zu\\\\n", my_strlen(str1));
\n \/\/ \u8f93\u51fa 0
\n printf("my_strlen(\\\\"\\\\") = %zu\\\\n", my_strlen(str2));
\n return 0;
\n}<\/p>\n
strcpy \u5c06\u6e90\u5b57\u7b26\u4e32（\u5305\u542b '\\\\0'）\u5b8c\u6574\u62f7\u8d1d\u5230\u76ee\u6807\u7f13\u51b2\u533a，\u8981\u6c42\u76ee\u6807\u7f13\u51b2\u533a\u8db3\u591f\u5927，\u5426\u5219\u4f1a\u5bfc\u81f4\u7f13\u51b2\u533a\u6ea2\u51fa\u3002<\/p>\n
c<\/p>\n
\u8fd0\u884c<\/p>\n
#include <stdio.h>
\n#include <string.h><\/p>\n
int main() {
\n char dest[20]; \/\/ \u76ee\u6807\u7f13\u51b2\u533a
\n char src[] = "Hello C";
\n strcpy(dest, src); \/\/ \u62f7\u8d1dsrc\u5230dest
\n printf("\u62f7\u8d1d\u7ed3\u679c：%s\\\\n", dest); \/\/ \u8f93\u51fa Hello C
\n return 0;
\n}<\/p>\n
c<\/p>\n
\u8fd0\u884c<\/p>\n
#include <stdio.h>
\n#include <assert.h><\/p>\n
\/\/ \u624b\u52a8\u5b9e\u73b0strcpy：\u9010\u5b57\u7b26\u62f7\u8d1d
\nchar *my_strcpy(char *dest, const char *src) {
\n \/\/ \u68c0\u67e5\u76ee\u6807\u548c\u6e90\u6307\u9488\u662f\u5426\u4e3a\u7a7a
\n assert(dest != NULL && src != NULL);
\n char *p = dest; \/\/ \u4fdd\u5b58\u76ee\u6807\u7f13\u51b2\u533a\u8d77\u59cb\u5730\u5740（\u7528\u4e8e\u8fd4\u56de）
\n \/\/ \u9010\u5b57\u7b26\u62f7\u8d1d，\u76f4\u5230src\u7684'\\\\0'（*src\u4e3a'\\\\0'\u65f6，\u8d4b\u503c\u540e\u5faa\u73af\u7ec8\u6b62）
\n while ((*p++ = *src++) != '\\\\0');
\n return dest; \/\/ \u8fd4\u56de\u76ee\u6807\u7f13\u51b2\u533a\u5730\u5740，\u652f\u6301\u94fe\u5f0f\u8c03\u7528
\n}<\/p>\n
\/\/ \u6d4b\u8bd5\u4ee3\u7801
\nint main() {
\n char dest[20];
\n char src[] = "String Copy";
\n my_strcpy(dest, src);
\n printf("my_strcpy\u7ed3\u679c：%s\\\\n", dest); \/\/ \u8f93\u51fa String Copy
\n return 0;
\n}<\/p>\n
strcat \u5c06\u6e90\u5b57\u7b26\u4e32\u62fc\u63a5\u5230\u76ee\u6807\u5b57\u7b26\u4e32\u7684\u672b\u5c3e（\u8986\u76d6\u76ee\u6807\u539f\u6709\u7684 '\\\\0'，\u6700\u7ec8\u6dfb\u52a0\u65b0\u7684 '\\\\0'）\u3002<\/p>\n
c<\/p>\n
\u8fd0\u884c<\/p>\n
#include <stdio.h>
\n#include <string.h><\/p>\n
int main() {
\n char dest[30] = "Hello, "; \/\/ \u76ee\u6807\u5b57\u7b26\u4e32
\n char src[] = "World!";
\n strcat(dest, src); \/\/ \u62fc\u63a5src\u5230dest\u672b\u5c3e
\n printf("\u62fc\u63a5\u7ed3\u679c：%s\\\\n", dest); \/\/ \u8f93\u51fa Hello, World!
\n return 0;
\n}<\/p>\n
c<\/p>\n
\u8fd0\u884c<\/p>\n
#include <stdio.h>
\n#include <assert.h><\/p>\n
\/\/ \u624b\u52a8\u5b9e\u73b0strcat：\u5148\u627e\u76ee\u6807\u672b\u5c3e，\u518d\u62f7\u8d1d\u6e90\u5b57\u7b26\u4e32
\nchar *my_strcat(char *dest, const char *src) {
\n assert(dest != NULL && src != NULL);
\n char *p = dest;
\n \/\/ \u7b2c\u4e00\u6b65：\u627e\u5230\u76ee\u6807\u5b57\u7b26\u4e32\u7684'\\\\0'\u4f4d\u7f6e
\n while (*p != '\\\\0') {
\n p++;
\n }
\n \/\/ \u7b2c\u4e8c\u6b65：\u4ece'\\\\0'\u4f4d\u7f6e\u5f00\u59cb\u62f7\u8d1d\u6e90\u5b57\u7b26\u4e32（\u590d\u7528strcpy\u903b\u8f91）
\n while ((*p++ = *src++) != '\\\\0');
\n return dest;
\n}<\/p>\n
\/\/ \u6d4b\u8bd5\u4ee3\u7801
\nint main() {
\n char dest[30] = "I love ";
\n char src[] = "C Programming";
\n my_strcat(dest, src);
\n printf("my_strcat\u7ed3\u679c：%s\\\\n", dest); \/\/ \u8f93\u51fa I love C Programming
\n return 0;
\n}<\/p>\n
strcmp \u6309 ASCII \u7801\u503c\u9010\u5b57\u7b26\u6bd4\u8f83\u4e24\u4e2a\u5b57\u7b26\u4e32，\u8fd4\u56de\u503c\u89c4\u5219：<\/p>\n
c<\/p>\n
\u8fd0\u884c<\/p>\n
#include <stdio.h>
\n#include <string.h><\/p>\n
int main() {
\n char str1[] = "Apple";
\n char str2[] = "Banana";
\n char str3[] = "Apple";<\/p>\n
int ret1 = strcmp(str1, str2); \/\/ Apple < Banana，\u8fd4\u56de\u8d1f\u6570
\n int ret2 = strcmp(str1, str3); \/\/ \u76f8\u7b49，\u8fd4\u56de0
\n int ret3 = strcmp(str2, str1); \/\/ Banana > Apple，\u8fd4\u56de\u6b63\u6570<\/p>\n
printf("strcmp(Apple, Banana) = %d\\\\n", ret1); \/\/ \u8f93\u51fa -1
\n printf("strcmp(Apple, Apple) = %d\\\\n", ret2); \/\/ \u8f93\u51fa 0
\n printf("strcmp(Banana, Apple) = %d\\\\n", ret3); \/\/ \u8f93\u51fa 1
\n return 0;
\n}<\/p>\n
c<\/p>\n
\u8fd0\u884c<\/p>\n
#include <stdio.h>
\n#include <assert.h><\/p>\n
\/\/ \u624b\u52a8\u5b9e\u73b0strcmp：\u9010\u5b57\u7b26\u6bd4\u8f83ASCII\u503c
\nint my_strcmp(const char *str1, const char *str2) {
\n assert(str1 != NULL && str2 != NULL);
\n \/\/ \u904d\u5386\u76f4\u5230\u5b57\u7b26\u4e0d\u540c\u6216\u90fd\u5230'\\\\0'
\n while (*str1 != '\\\\0' && *str2 != '\\\\0' && *str1 == *str2) {
\n str1++;
\n str2++;
\n }
\n \/\/ \u8fd4\u56de\u7b2c\u4e00\u4e2a\u4e0d\u540c\u5b57\u7b26\u7684ASCII\u5dee\u503c（unsigned char\u907f\u514d\u8d1f\u6570\u6ea2\u51fa）
\n return (unsigned char)*str1 – (unsigned char)*str2;
\n}<\/p>\n
\/\/ \u6d4b\u8bd5\u4ee3\u7801
\nint main() {
\n char str1[] = "Cat";
\n char str2[] = "Car";
\n char str3[] = "Cat";<\/p>\n
printf("my_strcmp(Cat, Car) = %d\\\\n", my_strcmp(str1, str2)); \/\/ t(116)-r(114)=2
\n printf("my_strcmp(Cat, Cat) = %d\\\\n", my_strcmp(str1, str3)); \/\/ 0
\n printf("my_strcmp(Car, Cat) = %d\\\\n", my_strcmp(str2, str1)); \/\/ -2
\n return 0;
\n}<\/p>\n
strchr \u5728\u5b57\u7b26\u4e32\u4e2d\u67e5\u627e\u6307\u5b9a\u5b57\u7b26\u9996\u6b21\u51fa\u73b0\u7684\u4f4d\u7f6e，\u8fd4\u56de\u8be5\u4f4d\u7f6e\u7684\u6307\u9488；\u82e5\u627e\u4e0d\u5230，\u8fd4\u56de NULL\u3002<\/p>\n
c<\/p>\n
\u8fd0\u884c<\/p>\n
#include <stdio.h>
\n#include <string.h><\/p>\n
int main() {
\n char str[] = "Hello World";
\n char *p = strchr(str, 'o'); \/\/ \u67e5\u627e\u5b57\u7b26'o'
\n if (p != NULL) {
\n \/\/ \u8f93\u51fa \u9996\u6b21\u51fa\u73b0\u4f4d\u7f6e：o World（\u4eceo\u5f00\u59cb\u7684\u5b50\u4e32）
\n printf("\u9996\u6b21\u51fa\u73b0\u4f4d\u7f6e：%s\\\\n", p);
\n \/\/ \u8f93\u51fa \u7d22\u5f15：4（o\u5728\u5b57\u7b26\u4e32\u4e2d\u662f\u7b2c5\u4e2a\u5b57\u7b26，\u7d22\u5f15\u4ece0\u5f00\u59cb）
\n printf("\u7d22\u5f15：%zu\\\\n", p – str);
\n } else {
\n printf("\u672a\u627e\u5230\u5b57\u7b26\\\\n");
\n }
\n return 0;
\n}<\/p>\n
c<\/p>\n
\u8fd0\u884c<\/p>\n
#include <stdio.h>
\n#include <assert.h><\/p>\n
\/\/ \u624b\u52a8\u5b9e\u73b0strchr：\u67e5\u627e\u5b57\u7b26\u9996\u6b21\u51fa\u73b0\u4f4d\u7f6e
\nchar *my_strchr(const char *str, int ch) {
\n assert(str != NULL);
\n \/\/ \u6ce8\u610f：ch\u4f1a\u88ab\u8f6c\u4e3aunsigned char，\u7edf\u4e00\u5b57\u7b26\u7c7b\u578b
\n unsigned char target = (unsigned char)ch;
\n \/\/ \u904d\u5386\u5b57\u7b26\u4e32
\n while (*str != '\\\\0') {
\n if ((unsigned char)*str == target) {
\n return (char *)str; \/\/ \u627e\u5230\u5219\u8fd4\u56de\u5f53\u524d\u6307\u9488
\n }
\n str++;
\n }
\n \/\/ \u7279\u6b8a\u60c5\u51b5：\u67e5\u627e\u7684\u662f'\\\\0'（\u5b57\u7b26\u4e32\u7ed3\u675f\u7b26）
\n if (target == '\\\\0') {
\n return (char *)str;
\n }
\n return NULL; \/\/ \u672a\u627e\u5230\u8fd4\u56deNULL
\n}<\/p>\n
\/\/ \u6d4b\u8bd5\u4ee3\u7801
\nint main() {
\n char str[] = "Programming";
\n char *p1 = my_strchr(str, 'g');
\n char *p2 = my_strchr(str, 'z');<\/p>\n
if (p1) {
\n printf("\u627e\u5230'g'：%s，\u7d22\u5f15：%zu\\\\n", p1, p1 – str); \/\/ \u8f93\u51fa \u627e\u5230'g'：gramming，\u7d22\u5f15：3
\n }
\n if (p2 == NULL) {
\n printf("\u672a\u627e\u5230'z'\\\\n"); \/\/ \u8f93\u51fa \u672a\u627e\u5230'z'
\n }
\n return 0;
\n}<\/p>\n
\u8fd9\u4e9b\u624b\u52a8\u5b9e\u73b0\u7684\u51fd\u6570\u4e0e\u6807\u51c6\u5e93\u903b\u8f91\u4e00\u81f4（\u7b80\u5316\u7248），\u4f60\u53ef\u4ee5\u57fa\u4e8e\u8fd9\u4e9b\u4ee3\u7801\u6269\u5c55\u529f\u80fd（\u6bd4\u5982\u5b9e\u73b0 strncpy\u3001strncat \u7b49\u5e26\u957f\u5ea6\u9650\u5236\u7684\u5b89\u5168\u7248\u672c）\u3002<\/p>\n
\u6dfb\u52a0strncpy\u3001strncat\u7b49<\/p>\n
\u5df2\u5b8c\u6210\u601d\u8003<\/p>\n
\u7528\u6237\u73b0\u5728\u8981\u6c42\u6dfb\u52a0 strncpy\u3001strncat \u7b49\u5b57\u7b26\u4e32\u5904\u7406\u51fd\u6570\u7684\u6e90\u4ee3\u7801\u548c\u5b9e\u4f8b，\u9996\u5148\u6211\u9700\u8981\u5148\u590d\u8ff0\u7528\u6237\u7684\u6838\u5fc3\u9700\u6c42：\u7528\u6237\u5e0c\u671b\u5728\u4e4b\u524d\u8bb2\u89e3\u7684 strlen\u3001strcpy \u7b49\u51fd\u6570\u57fa\u7840\u4e0a，\u8865\u5145 strncpy\u3001strncat \u8fd9\u4e24\u4e2a\u5e26\u957f\u5ea6\u9650\u5236\u7684\u5b89\u5168\u7248\u5b57\u7b26\u4e32\u51fd\u6570\u7684\u529f\u80fd\u8bf4\u660e\u3001\u6807\u51c6\u5e93\u4f7f\u7528\u5b9e\u4f8b\u3001\u624b\u52a8\u5b9e\u73b0\u6e90\u4ee3\u7801\u548c\u5173\u952e\u903b\u8f91\u89e3\u91ca，\u5e2e\u52a9\u7406\u89e3\u8fd9\u7c7b\u5b89\u5168\u7248\u51fd\u6570\u7684\u5e95\u5c42\u5b9e\u73b0\u548c\u4f7f\u7528\u8981\u70b9\u3002<\/p>\n
\u63a5\u4e0b\u6765，\u6309\u7167\u4e4b\u524d\u7684\u7ed3\u6784\u6765\u7ec4\u7ec7\u5185\u5bb9，\u5148\u8bb2 strncpy，\u518d\u8bb2 strncat，\u6bcf\u4e2a\u90e8\u5206\u90fd\u5305\u542b\u529f\u80fd\u8bf4\u660e\u3001\u6807\u51c6\u5e93\u5b9e\u4f8b\u3001\u624b\u52a8\u5b9e\u73b0\u3001\u5173\u952e\u89e3\u91ca，\u6700\u540e\u8fd8\u8981\u8865\u5145\u603b\u7ed3，\u628a\u65b0\u589e\u7684\u8981\u70b9\u52a0\u8fdb\u53bb\u3002<\/p>\n
\u9996\u5148\u5904\u7406 strncpy：<\/p>\n
\u7136\u540e\u662f strncat：<\/p>\n
\u8fd8\u8981\u6ce8\u610f\u4fdd\u6301\u548c\u4e4b\u524d\u4e00\u81f4\u7684\u98ce\u683c，\u4ee3\u7801\u6ce8\u91ca\u6e05\u6670，\u5b9e\u4f8b\u6709\u8f93\u51fa\u8bf4\u660e，\u5173\u952e\u903b\u8f91\u7528\u7c97\u4f53\u5f3a\u8c03，\u6700\u540e\u603b\u7ed3\u90e8\u5206\u8981\u8865\u5145\u8fd9\u4e24\u4e2a\u5b89\u5168\u51fd\u6570\u7684\u6838\u5fc3\u8981\u70b9\u3002<\/p>\n
\u73b0\u5728\u5f00\u59cb\u7ec4\u7ec7\u5185\u5bb9，\u9996\u5148\u590d\u8ff0\u9700\u6c42，\u7136\u540e\u4f9d\u6b21\u8bb2\u89e3 strncpy\u3001strncat，\u6700\u540e\u603b\u7ed3\u65b0\u589e\u7684\u5173\u952e\u70b9\u3002<\/p>\n
\u4f60\u5e0c\u671b\u5728\u4e4b\u524d\u7684\u57fa\u7840\u4e0a，\u8865\u5145 strncpy\u3001strncat \u8fd9\u4e24\u4e2a\u5e26\u957f\u5ea6\u9650\u5236\u7684\u5b89\u5168\u7248\u5b57\u7b26\u4e32\u51fd\u6570（\u89e3\u51b3 strcpy\/strcat \u7f13\u51b2\u533a\u6ea2\u51fa\u7684\u95ee\u9898），\u4e0b\u9762\u4e3a\u4f60\u8be6\u7ec6\u8bb2\u89e3\u8fd9\u4e24\u4e2a\u51fd\u6570\u7684\u529f\u80fd\u3001\u6807\u51c6\u5e93\u4f7f\u7528\u5b9e\u4f8b\u3001\u624b\u52a8\u5b9e\u73b0\u6e90\u4ee3\u7801\u53ca\u6838\u5fc3\u903b\u8f91\u89e3\u91ca\u3002<\/p>\n
strncpy \u662f strcpy \u7684\u5b89\u5168\u7248\u672c，\u6838\u5fc3\u662f\u9650\u5236\u62f7\u8d1d\u7684\u6700\u5927\u5b57\u7b26\u6570，\u907f\u514d\u7f13\u51b2\u533a\u6ea2\u51fa\u3002\u5173\u952e\u89c4\u5219：<\/p>\n
c<\/p>\n
\u8fd0\u884c<\/p>\n
#include <stdio.h>
\n#include <string.h><\/p>\n
int main() {
\n \/\/ \u573a\u666f1：\u6e90\u5b57\u7b26\u4e32\u957f\u5ea6 < n
\n char dest1[10];
\n char src1[] = "Hi";
\n strncpy(dest1, src1, 5); \/\/ \u62f7\u8d1dHi，\u518d\u586b3\u4e2a'\\\\0'\u5230\u603b\u957f\u5ea65
\n printf("\u573a\u666f1：dest1 = %s（\u957f\u5ea6：%zu）\\\\n", dest1, strlen(dest1)); \/\/ \u8f93\u51fa Hi（\u957f\u5ea62）<\/p>\n
\u7ed9\u51fa\u5b8c\u6574\u7684c\u8bed\u8a00\u5b57\u7b26\u4e32\u5904\u7406\u51fd\u6570<\/p>\n
\u5df2\u5b8c\u6210\u601d\u8003<\/p>\n
\u7528\u6237\u73b0\u5728\u9700\u8981\u5b8c\u6574\u7684 C \u8bed\u8a00\u5b57\u7b26\u4e32\u5904\u7406\u51fd\u6570，\u5305\u62ec\u4e4b\u524d\u7684 strlen\u3001strcpy\u3001strcat\u3001strcmp\u3001strchr，\u52a0\u4e0a strncpy\u3001strncat，\u8fd8\u8981\u8865\u5145 strncmp\u3001strstr\u3001strtok\u3001memset \u8fd9\u4e9b\u5e38\u7528\u7684，\u6bcf\u4e2a\u90fd\u8981\u6709\u529f\u80fd\u8bf4\u660e\u3001\u6807\u51c6\u5e93\u793a\u4f8b\u3001\u624b\u52a8\u5b9e\u73b0\u3001\u903b\u8f91\u89e3\u91ca，\u6700\u540e\u603b\u7ed3\u3002<\/p>\n
\u9996\u5148，\u5148\u68b3\u7406\u7ed3\u6784，\u6bcf\u4e2a\u51fd\u6570\u6309\u7edf\u4e00\u7684\u683c\u5f0f：\u529f\u80fd\u8bf4\u660e\u3001\u6807\u51c6\u5e93\u4f7f\u7528\u5b9e\u4f8b\u3001\u624b\u52a8\u5b9e\u73b0\u6e90\u4ee3\u7801\u3001\u5173\u952e\u903b\u8f91\u89e3\u91ca\u3002<\/p>\n
\u9996\u5148，\u5148\u660e\u786e\u7528\u6237\u7684\u6838\u5fc3\u9700\u6c42：\u5b8c\u6574\u7684\u5e38\u7528 C \u8bed\u8a00\u5b57\u7b26\u4e32\u5904\u7406\u51fd\u6570，\u5305\u542b\u5b89\u5168\u7248（\u5e26 n \u7684），\u6bcf\u4e2a\u90fd\u6709\u5b9e\u73b0\u548c\u793a\u4f8b，\u9002\u5408\u65b0\u624b\u7406\u89e3\u3002<\/p>\n
\u7136\u540e，\u5f00\u59cb\u7ec4\u7ec7\u5185\u5bb9：<\/p>\n
\u7136\u540e\u5206\u51fd\u6570\u8bb2\u89e3：<\/p>\n
\u6bcf\u4e2a\u90e8\u5206\u6309\u683c\u5f0f\u6765，\u786e\u4fdd\u4ee3\u7801\u5b8c\u6574\u53ef\u8fd0\u884c，\u89e3\u91ca\u6e05\u6670，\u91cd\u70b9\u7a81\u51fa\u5b89\u5168\u70b9\u548c\u6613\u9519\u70b9\u3002<\/p>\n
\u7136\u540e\u6700\u540e\u603b\u7ed3\u5173\u952e\u70b9\u3002<\/p>\n
\u73b0\u5728\u5f00\u59cb\u5199\u5177\u4f53\u5185\u5bb9，\u786e\u4fdd\u4ee3\u7801\u6b63\u786e，\u89e3\u91ca\u901a\u4fd7\u6613\u61c2，\u9002\u5408\u65b0\u624b\u3002<\/p>\n
\u4f60\u9700\u8981\u4e00\u5957\u5b8c\u6574\u7684\u3001\u5e38\u7528\u7684 C \u8bed\u8a00\u5b57\u7b26\u4e32\u5904\u7406\u51fd\u6570\u5b9e\u73b0（\u5305\u542b\u57fa\u7840\u7248\u548c\u5b89\u5168\u7248），\u4e0b\u9762\u6574\u7406\u4e86 10 \u4e2a\u6838\u5fc3\u51fd\u6570，\u8986\u76d6\u62f7\u8d1d\u3001\u62fc\u63a5\u3001\u6bd4\u8f83\u3001\u67e5\u627e\u3001\u5206\u5272\u3001\u5185\u5b58\u586b\u5145\u7b49\u573a\u666f，\u6bcf\u4e2a\u51fd\u6570\u90fd\u5305\u542b\u529f\u80fd\u8bf4\u660e\u3001\u6807\u51c6\u5e93\u4f7f\u7528\u5b9e\u4f8b\u3001\u624b\u52a8\u5b9e\u73b0\u6e90\u4ee3\u7801\u548c\u5173\u952e\u903b\u8f91\u89e3\u91ca，\u4ee3\u7801\u53ef\u76f4\u63a5\u7f16\u8bd1\u8fd0\u884c，\u4e14\u6807\u6ce8\u4e86\u65b0\u624b\u6613\u51fa\u9519\u7684\u7ec6\u8282\u3002<\/p>\n
\u6240\u6709\u5b57\u7b26\u4e32\u51fd\u6570\u7684\u6838\u5fc3\u524d\u63d0：C \u8bed\u8a00\u5b57\u7b26\u4e32\u4ee5 '\\\\0'（\u7a7a\u5b57\u7b26）\u4f5c\u4e3a\u7ed3\u675f\u6807\u5fd7，\u624b\u52a8\u5b9e\u73b0\u65f6\u5fc5\u987b\u56f4\u7ed5 '\\\\0' \u5904\u7406，\u540c\u65f6\u91cd\u70b9\u5173\u6ce8\u7a7a\u6307\u9488\u68c0\u67e5\u548c\u7f13\u51b2\u533a\u6ea2\u51fa\u95ee\u9898\u3002<\/p>\n
\u8ba1\u7b97\u5b57\u7b26\u4e32\u6709\u6548\u957f\u5ea6（\u4e0d\u542b '\\\\0'），\u8fd4\u56de\u65e0\u7b26\u53f7\u6574\u6570 size_t\u3002<\/p>\n
c<\/p>\n
\u8fd0\u884c<\/p>\n
#include <stdio.h>
\n#include <string.h><\/p>\n
int main() {
\n char str[] = "Hello C";
\n printf("\u957f\u5ea6：%zu\\\\n", strlen(str)); \/\/ \u8f93\u51fa 7（H\u5230C\u51717\u4e2a\u5b57\u7b26）
\n return 0;
\n}<\/p>\n
c<\/p>\n
\u8fd0\u884c<\/p>\n
#include <stdio.h>
\n#include <assert.h><\/p>\n
size_t my_strlen(const char *str) {
\n assert(str != NULL); \/\/ \u7a7a\u6307\u9488\u68c0\u67e5，\u907f\u514d\u5d29\u6e83
\n const char *p = str;
\n while (*p != '\\\\0') { \/\/ \u904d\u5386\u5230'\\\\0'\u7ec8\u6b62
\n p++;
\n }
\n return p – str; \/\/ \u6307\u9488\u5dee\u503c = \u5b57\u7b26\u6570
\n}<\/p>\n
\/\/ \u6d4b\u8bd5
\nint main() {
\n printf("%zu\\\\n", my_strlen("Test")); \/\/ 4
\n printf("%zu\\\\n", my_strlen("")); \/\/ 0
\n return 0;
\n}<\/p>\n
\u5c06\u6e90\u5b57\u7b26\u4e32（\u542b '\\\\0'）\u5b8c\u6574\u62f7\u8d1d\u5230\u76ee\u6807\u7f13\u51b2\u533a，\u6613\u6ea2\u51fa，\u4ec5\u9002\u5408\u786e\u5b9a\u7f13\u51b2\u533a\u8db3\u591f\u5927\u7684\u573a\u666f\u3002<\/p>\n
c<\/p>\n
\u8fd0\u884c<\/p>\n
#include <stdio.h>
\n#include <string.h><\/p>\n
int main() {
\n char dest[20];
\n char src[] = "String Copy";
\n strcpy(dest, src);
\n printf("\u62f7\u8d1d\u7ed3\u679c：%s\\\\n", dest); \/\/ \u8f93\u51fa String Copy
\n return 0;
\n}<\/p>\n
c<\/p>\n
\u8fd0\u884c<\/p>\n
#include <stdio.h>
\n#include <assert.h><\/p>\n
char *my_strcpy(char *dest, const char *src) {
\n assert(dest != NULL && src != NULL); \/\/ \u53cc\u6307\u9488\u975e\u7a7a\u68c0\u67e5
\n char *p = dest; \/\/ \u4fdd\u5b58\u76ee\u6807\u8d77\u59cb\u5730\u5740（\u7528\u4e8e\u8fd4\u56de）
\n while ((*p++ = *src++) != '\\\\0'); \/\/ \u9010\u5b57\u7b26\u62f7\u8d1d，\u5305\u542b'\\\\0'
\n return dest; \/\/ \u8fd4\u56de\u76ee\u6807\u5730\u5740，\u652f\u6301\u94fe\u5f0f\u8c03\u7528
\n}<\/p>\n
\/\/ \u6d4b\u8bd5
\nint main() {
\n char dest[20];
\n my_strcpy(dest, "Hello Copy");
\n printf("%s\\\\n", dest); \/\/ Hello Copy
\n return 0;
\n}<\/p>\n
strcpy \u7684\u5b89\u5168\u7248\u672c，\u9650\u5236\u6700\u5927\u62f7\u8d1d\u5b57\u7b26\u6570 n，\u89e3\u51b3\u6ea2\u51fa\u95ee\u9898，\u6613\u9519\u70b9：<\/p>\n
c<\/p>\n
\u8fd0\u884c<\/p>\n
#include <stdio.h>
\n#include <string.h><\/p>\n
int main() {
\n \/\/ \u573a\u666f1：\u6e90\u957f\u5ea6 < n
\n char dest1[10];
\n strncpy(dest1, "Hi", 5); \/\/ \u62f7\u8d1d"Hi" + 3\u4e2a'\\\\0'
\n printf("dest1：%s（\u957f\u5ea6%zu）\\\\n", dest1, strlen(dest1)); \/\/ Hi（2）<\/p>\n
\/\/ \u573a\u666f2：\u6e90\u957f\u5ea6 \u2265 n（\u624b\u52a8\u52a0'\\\\0'）
\n char dest2[10];
\n strncpy(dest2, "HelloWorld", 5); \/\/ \u4ec5\u62f7\u8d1d"Hello"，\u65e0'\\\\0'
\n dest2[5] = '\\\\0'; \/\/ \u5fc5\u987b\u624b\u52a8\u8865'\\\\0'，\u5426\u5219\u4f1a\u4e71\u7801
\n printf("dest2：%s\\\\n", dest2); \/\/ Hello
\n return 0;
\n}<\/p>\n
c<\/p>\n
\u8fd0\u884c<\/p>\n
#include <stdio.h>
\n#include <assert.h><\/p>\n
char *my_strncpy(char *dest, const char *src, size_t n) {
\n assert(dest != NULL && src != NULL);
\n char *p = dest;
\n size_t i = 0;<\/p>\n
\/\/ \u7b2c\u4e00\u6b65：\u62f7\u8d1d\u6e90\u5b57\u7b26\u4e32，\u6700\u591an\u4e2a\u5b57\u7b26
\n while (i < n && *src != '\\\\0') {
\n *p++ = *src++;
\n i++;
\n }<\/p>\n
\/\/ \u7b2c\u4e8c\u6b65：\u6e90\u957f\u5ea6 < n，\u7528'\\\\0'\u586b\u5145\u5269\u4f59\u4f4d\u7f6e
\n while (i < n) {
\n *p++ = '\\\\0';
\n i++;
\n }<\/p>\n
return dest;
\n}<\/p>\n
\/\/ \u6d4b\u8bd5
\nint main() {
\n char dest1[10];
\n my_strncpy(dest1, "Test", 6);
\n printf("dest1：%s\\\\n", dest1); \/\/ Test（\u540e\u88652\u4e2a'\\\\0'）<\/p>\n
char dest2[10];
\n my_strncpy(dest2, "1234567890", 5);
\n dest2[5] = '\\\\0'; \/\/ \u624b\u52a8\u8865'\\\\0'
\n printf("dest2：%s\\\\n", dest2); \/\/ 12345
\n return 0;
\n}<\/p>\n
\u5c06\u6e90\u5b57\u7b26\u4e32\u62fc\u63a5\u5230\u76ee\u6807\u5b57\u7b26\u4e32\u672b\u5c3e（\u8986\u76d6\u76ee\u6807\u539f\u6709 '\\\\0'，\u6700\u7ec8\u52a0\u65b0 '\\\\0'），\u6613\u6ea2\u51fa\u3002<\/p>\n
c<\/p>\n
\u8fd0\u884c<\/p>\n
#include <stdio.h>
\n#include <string.h><\/p>\n
int main() {
\n char dest[30] = "I love ";
\n strcat(dest, "C Language");
\n printf("\u62fc\u63a5\u7ed3\u679c：%s\\\\n", dest); \/\/ I love C Language
\n return 0;
\n}<\/p>\n
c<\/p>\n
\u8fd0\u884c<\/p>\n
#include <stdio.h>
\n#include <assert.h><\/p>\n
char *my_strcat(char *dest, const char *src) {
\n assert(dest != NULL && src != NULL);
\n char *p = dest;<\/p>\n
\/\/ \u7b2c\u4e00\u6b65：\u627e\u5230\u76ee\u6807\u5b57\u7b26\u4e32\u7684'\\\\0'\u4f4d\u7f6e
\n while (*p != '\\\\0') {
\n p++;
\n }<\/p>\n
\/\/ \u7b2c\u4e8c\u6b65：\u4ece'\\\\0'\u5f00\u59cb\u62f7\u8d1d\u6e90\u5b57\u7b26\u4e32（\u540cstrcpy\u903b\u8f91）
\n while ((*p++ = *src++) != '\\\\0');
\n return dest;
\n}<\/p>\n
\/\/ \u6d4b\u8bd5
\nint main() {
\n char dest[30] = "Hello, ";
\n my_strcat(dest, "World!");
\n printf("%s\\\\n", dest); \/\/ Hello, World!
\n return 0;
\n}<\/p>\n
strcat \u7684\u5b89\u5168\u7248\u672c，\u9650\u5236\u6700\u591a\u62fc\u63a5 n \u4e2a\u5b57\u7b26，\u6838\u5fc3\u4f18\u52bf：<\/p>\n
c<\/p>\n
\u8fd0\u884c<\/p>\n
#include <stdio.h>
\n#include <string.h><\/p>\n
int main() {
\n char dest[20] = "Hello, ";
\n strncat(dest, "1234567890", 3); \/\/ \u4ec5\u62fc\u63a5\u524d3\u4e2a\u5b57\u7b26"123"
\n printf("\u62fc\u63a5\u7ed3\u679c：%s\\\\n", dest); \/\/ Hello, 123
\n return 0;
\n}<\/p>\n
c<\/p>\n
\u8fd0\u884c<\/p>\n
#include <stdio.h>
\n#include <assert.h><\/p>\n
char *my_strncat(char *dest, const char *src, size_t n) {
\n assert(dest != NULL && src != NULL);
\n char *p = dest;
\n size_t i = 0;<\/p>\n
\/\/ \u7b2c\u4e00\u6b65：\u627e\u5230\u76ee\u6807\u7684'\\\\0'
\n while (*p != '\\\\0') {
\n p++;
\n }<\/p>\n
\/\/ \u7b2c\u4e8c\u6b65：\u62fc\u63a5\u6700\u591an\u4e2a\u5b57\u7b26，\u4e0d\u5305\u542b\u6e90\u7684'\\\\0'
\n while (i < n && *src != '\\\\0') {
\n *p++ = *src++;
\n i++;
\n }<\/p>\n
\/\/ \u7b2c\u4e09\u6b65：\u624b\u52a8\u52a0'\\\\0'（\u6838\u5fc3\u5b89\u5168\u70b9）
\n *p = '\\\\0';
\n return dest;
\n}<\/p>\n
\/\/ \u6d4b\u8bd5
\nint main() {
\n char dest[20] = "Test: ";
\n my_strncat(dest, "ABCDEFG", 4);
\n printf("%s\\\\n", dest); \/\/ Test: ABCD
\n return 0;
\n}<\/p>\n
\u6309 ASCII \u7801\u9010\u5b57\u7b26\u6bd4\u8f83，\u8fd4\u56de\u503c\u89c4\u5219：<\/p>\n
0：str1 \u5927\u4e8e str2\u3002<\/p>\n<\/li>\n<\/ul>\n
c<\/p>\n
\u8fd0\u884c<\/p>\n
#include <stdio.h>
\n#include <string.h><\/p>\n
int main() {
\n printf("%d\\\\n", strcmp("Apple", "Banana")); \/\/ -1（A(65)<B(66)）
\n printf("%d\\\\n", strcmp("Apple", "Apple")); \/\/ 0
\n printf("%d\\\\n", strcmp("Banana", "Apple")); \/\/ 1
\n return 0;
\n}<\/p>\n
c<\/p>\n
\u8fd0\u884c<\/p>\n
#include <stdio.h>
\n#include <assert.h><\/p>\n
int my_strcmp(const char *str1, const char *str2) {
\n assert(str1 != NULL && str2 != NULL);
\n \/\/ \u904d\u5386\u5230\u5b57\u7b26\u4e0d\u540c\u6216\u5230'\\\\0'
\n while (*str1 != '\\\\0' && *str2 != '\\\\0' && *str1 == *str2) {
\n str1++;
\n str2++;
\n }
\n \/\/ \u8f6c\u4e3aunsigned char\u907f\u514d\u8d1f\u6570\u6ea2\u51fa（\u5982ASCII 0~255）
\n return (unsigned char)*str1 – (unsigned char)*str2;
\n}<\/p>\n
\/\/ \u6d4b\u8bd5
\nint main() {
\n printf("%d\\\\n", my_strcmp("Cat", "Car")); \/\/ 2（t(116)-r(114)）
\n printf("%d\\\\n", my_strcmp("Car", "Cat")); \/\/ -2
\n return 0;
\n}<\/p>\n
\u6700\u591a\u6bd4\u8f83\u524d n \u4e2a\u5b57\u7b26，\u907f\u514d\u8d85\u957f\u5b57\u7b26\u4e32\u7684\u65e0\u6548\u6bd4\u8f83\u3002<\/p>\n
c<\/p>\n
\u8fd0\u884c<\/p>\n
#include <stdio.h>
\n#include <string.h><\/p>\n
int main() {
\n \/\/ \u524d3\u4e2a\u5b57\u7b26\u90fd\u662f"App"，\u8fd4\u56de0
\n printf("%d\\\\n", strncmp("Apple", "Application", 3));
\n \/\/ \u524d2\u4e2a\u5b57\u7b26"Ap"=="Ap"，\u7b2c3\u4e2a'p'>'p'? \u4e0d，\u7b2c3\u4e2a'p'=='p'，\u7b2c4\u4e2a'l'<'l'? \u793a\u4f8b：strncmp("Apple", "App", 3) \u2192 0
\n printf("%d\\\\n", strncmp("Apple", "App", 3)); \/\/ 0
\n return 0;
\n}<\/p>\n
c<\/p>\n
\u8fd0\u884c<\/p>\n
#include <stdio.h>
\n#include <assert.h><\/p>\n
int my_strncmp(const char *str1, const char *str2, size_t n) {
\n assert(str1 != NULL && str2 != NULL);
\n if (n == 0) return 0; \/\/ \u6bd4\u8f830\u4e2a\u5b57\u7b26，\u76f4\u63a5\u8fd4\u56de\u76f8\u7b49<\/p>\n
size_t i = 0;
\n \/\/ \u6700\u591a\u6bd4\u8f83n\u4e2a\u5b57\u7b26，\u4e14\u5b57\u7b26\u76f8\u7b49\u3001\u672a\u5230'\\\\0'
\n while (i < n-1 && *str1 != '\\\\0' && *str2 != '\\\\0' && *str1 == *str2) {
\n str1++;
\n str2++;
\n i++;
\n }<\/p>\n
return (unsigned char)*str1 – (unsigned char)*str2;
\n}<\/p>\n
\/\/ \u6d4b\u8bd5
\nint main() {
\n printf("%d\\\\n", my_strncmp("12345", "123678", 3)); \/\/ 0（\u524d3\u4e2a\u76f8\u7b49）
\n printf("%d\\\\n", my_strncmp("12345", "123678", 4)); \/\/ -2（4<6）
\n return 0;
\n}<\/p>\n
\u5728\u5b57\u7b26\u4e32\u4e2d\u67e5\u627e\u6307\u5b9a\u5b57\u7b26\u7684\u9996\u6b21\u51fa\u73b0\u4f4d\u7f6e，\u8fd4\u56de\u8be5\u4f4d\u7f6e\u6307\u9488；\u627e\u4e0d\u5230\u8fd4\u56de NULL\u3002<\/p>\n
c<\/p>\n
\u8fd0\u884c<\/p>\n
#include <stdio.h>
\n#include <string.h><\/p>\n
int main() {
\n char str[] = "Hello World";
\n char *p = strchr(str, 'o');
\n if (p != NULL) {
\n printf("\u627e\u5230：%s\\\\n", p); \/\/ o World
\n printf("\u7d22\u5f15：%zu\\\\n", p – str); \/\/ 4
\n }
\n return 0;
\n}<\/p>\n
c<\/p>\n
\u8fd0\u884c<\/p>\n
#include <stdio.h>
\n#include <assert.h><\/p>\n
char *my_strchr(const char *str, int ch) {
\n assert(str != NULL);
\n unsigned char target = (unsigned char)ch; \/\/ \u7edf\u4e00\u5b57\u7b26\u7c7b\u578b<\/p>\n
while (*str != '\\\\0') {
\n if ((unsigned char)*str == target) {
\n return (char *)str; \/\/ \u627e\u5230\u8fd4\u56de\u6307\u9488
\n }
\n str++;
\n }<\/p>\n
\/\/ \u7279\u6b8a\u60c5\u51b5：\u67e5\u627e\u7684\u662f'\\\\0'
\n if (target == '\\\\0') {
\n return (char *)str;
\n }<\/p>\n
return NULL; \/\/ \u672a\u627e\u5230
\n}<\/p>\n
\/\/ \u6d4b\u8bd5
\nint main() {
\n char *p = my_strchr("Programming", 'g');
\n printf("%s\\\\n", p); \/\/ gramming
\n return 0;
\n}<\/p>\n
\u5728\u5b57\u7b26\u4e32 str \u4e2d\u67e5\u627e\u5b50\u4e32 sub \u7684\u9996\u6b21\u51fa\u73b0\u4f4d\u7f6e，\u8fd4\u56de\u6307\u9488；\u627e\u4e0d\u5230\u8fd4\u56de NULL\u3002<\/p>\n
c<\/p>\n
\u8fd0\u884c<\/p>\n
#include <stdio.h>
\n#include <string.h><\/p>\n
int main() {
\n char str[] = "I love C Programming";
\n char *p = strstr(str, "Programming");
\n if (p != NULL) {
\n printf("\u627e\u5230\u5b50\u4e32：%s\\\\n", p); \/\/ Programming
\n }
\n return 0;
\n}<\/p>\n
c<\/p>\n
\u8fd0\u884c<\/p>\n
#include <stdio.h>
\n#include <assert.h><\/p>\n
char *my_strstr(const char *str, const char *sub) {
\n assert(str != NULL && sub != NULL);
\n if (*sub == '\\\\0') return (char *)str; \/\/ \u7a7a\u5b50\u4e32\u8fd4\u56de\u539f\u5b57\u7b26\u4e32<\/p>\n
const char *p_str = str;
\n const char *p_sub;<\/p>\n
\/\/ \u904d\u5386\u539f\u5b57\u7b26\u4e32
\n while (*p_str != '\\\\0') {
\n p_sub = sub;
\n const char *temp = p_str;<\/p>\n
\/\/ \u5339\u914d\u5b50\u4e32
\n while (*temp != '\\\\0' && *p_sub != '\\\\0' && *temp == *p_sub) {
\n temp++;
\n p_sub++;
\n }<\/p>\n
\/\/ \u5b50\u4e32\u5168\u90e8\u5339\u914d\u5b8c\u6210
\n if (*p_sub == '\\\\0') {
\n return (char *)p_str;
\n }<\/p>\n
p_str++;
\n }<\/p>\n
return NULL; \/\/ \u672a\u627e\u5230
\n}<\/p>\n
\/\/ \u6d4b\u8bd5
\nint main() {
\n char *p = my_strstr("HelloWorldHello", "World");
\n printf("%s\\\\n", p); \/\/ WorldHello
\n return 0;
\n}<\/p>\n
\u6309\u6307\u5b9a\u5206\u9694\u7b26（\u5982 ,\u3001）\u5c06\u5b57\u7b26\u4e32\u62c6\u5206\u4e3a\u591a\u4e2a\u5b50\u4e32，\u6ce8\u610f：<\/p>\n
c<\/p>\n
\u8fd0\u884c<\/p>\n
#include <stdio.h>
\n#include <string.h><\/p>\n
int main() {
\n char str[] = "Apple,Banana,Cherry"; \/\/ \u5fc5\u987b\u662f\u53ef\u4fee\u6539\u7684\u6570\u7ec4（\u4e0d\u80fd\u662f\u5e38\u91cf\u5b57\u7b26\u4e32）
\n char *token = strtok(str, ","); \/\/ \u9996\u6b21\u8c03\u7528：\u4f20\u539f\u5b57\u7b26\u4e32+\u5206\u9694\u7b26
\n while (token != NULL) {
\n printf("\u5206\u5272\u7ed3\u679c：%s\\\\n", token); \/\/ Apple \u2192 Banana \u2192 Cherry
\n token = strtok(NULL, ","); \/\/ \u540e\u7eed\u8c03\u7528：\u4f20NULL
\n }
\n return 0;
\n}<\/p>\n
c<\/p>\n
\u8fd0\u884c<\/p>\n
#include <stdio.h>
\n#include <assert.h>
\n#include <string.h><\/p>\n
\/\/ \u9759\u6001\u53d8\u91cf\u4fdd\u5b58\u4e0a\u6b21\u5206\u5272\u7684\u4f4d\u7f6e
\nstatic char *last_pos = NULL;<\/p>\n
char *my_strtok(char *str, const char *delim) {
\n assert(delim != NULL);
\n if (str == NULL) {
\n str = last_pos; \/\/ \u540e\u7eed\u8c03\u7528：\u4ece\u4e0a\u6b21\u4f4d\u7f6e\u7ee7\u7eed
\n if (str == NULL) return NULL; \/\/ \u65e0\u5269\u4f59\u5b57\u7b26
\n }<\/p>\n
\/\/ \u7b2c\u4e00\u6b65：\u8df3\u8fc7\u5f00\u5934\u7684\u5206\u9694\u7b26
\n while (*str != '\\\\0' && strchr(delim, *str) != NULL) {
\n str++;
\n }<\/p>\n
\/\/ \u65e0\u6709\u6548\u5b57\u7b26
\n if (*str == '\\\\0') {
\n last_pos = NULL;
\n return NULL;
\n }<\/p>\n
\/\/ \u7b2c\u4e8c\u6b65：\u627e\u5230\u5206\u9694\u7b26\u4f4d\u7f6e，\u66ff\u6362\u4e3a'\\\\0'
\n char *token_start = str;
\n while (*str != '\\\\0' && strchr(delim, *str) == NULL) {
\n str++;
\n }<\/p>\n
if (*str != '\\\\0') {
\n *str = '\\\\0'; \/\/ \u5206\u9694\u7b26\u66ff\u6362\u4e3a'\\\\0'
\n last_pos = str + 1; \/\/ \u4fdd\u5b58\u4e0b\u6b21\u5206\u5272\u7684\u8d77\u59cb\u4f4d\u7f6e
\n } else {
\n last_pos = NULL; \/\/ \u5230\u672b\u5c3e，\u4e0b\u6b21\u8fd4\u56deNULL
\n }<\/p>\n
return token_start;
\n}<\/p>\n
\/\/ \u6d4b\u8bd5
\nint main() {
\n char str[] = "123 456 789";
\n char *token = my_strtok(str, " ");
\n while (token != NULL) {
\n printf("%s\\\\n", token); \/\/ 123 \u2192 456 \u2192 789
\n token = my_strtok(NULL, " ");
\n }
\n return 0;
\n}<\/p>\n
\u5c06\u6307\u5b9a\u5185\u5b58\u533a\u57df\u586b\u5145\u4e3a\u6307\u5b9a\u5b57\u7b26（\u5e38\u7528\u4e8e\u5b57\u7b26\u4e32\u521d\u59cb\u5316，\u5982\u6e05\u7a7a\u7f13\u51b2\u533a）\u3002<\/p>\n
c<\/p>\n
\u8fd0\u884c<\/p>\n
#include <stdio.h>
\n#include <string.h><\/p>\n
int main() {
\n char dest[20];
\n memset(dest, 0, sizeof(dest)); \/\/ \u5168\u90e8\u586b\u5145\u4e3a'\\\\0'
\n strcpy(dest, "Test");
\n printf("%s\\\\n", dest); \/\/ Test<\/p>\n
memset(dest, '*', 5); \/\/ \u524d5\u4e2a\u5b57\u7b26\u586b\u5145\u4e3a'*'
\n printf("%s\\\\n", dest); \/\/ *****
\n return 0;
\n}<\/p>\n
c<\/p>\n
\u8fd0\u884c<\/p>\n
#include <stdio.h>
\n#include <assert.h><\/p>\n
void *my_memset(void *ptr, int value, size_t num) {
\n assert(ptr != NULL);
\n unsigned char *p = (unsigned char *)ptr;
\n unsigned char val = (unsigned char)value;<\/p>\n
while (num– > 0) {
\n *p++ = val;
\n }<\/p>\n
return ptr; \/\/ \u8fd4\u56de\u539f\u6307\u9488，\u652f\u6301\u94fe\u5f0f\u8c03\u7528
\n}<\/p>\n
\/\/ \u6d4b\u8bd5
\nint main() {
\n char dest[20];
\n my_memset(dest, 0, sizeof(dest));
\n my_memset(dest, '#', 3);
\n printf("%s\\\\n", dest); \/\/ ###
\n return 0;
\n}<\/p>\n
\u4e00\u3001strlen：\u8ba1\u7b97\u5b57\u7b26\u4e32\u957f\u5ea6\u529f\u80fd\u8bf4\u660estrlen \u7528\u4e8e\u8ba1\u7b97\u5b57\u7b26\u4e32\u7684\u6709\u6548\u957f\u5ea6（\u4e0d\u5305\u542b\u5b57\u7b26\u4e32\u7ec8\u6b62\u7b26 \\\\0），\u533a\u522b\u4e8e sizeof（\u8ba1\u7b97\u5185\u5b58\u5927\u5c0f）\u3002\u6807\u51c6\u5e93\u4f7f\u7528\u5b9e\u4f8bc\u8fd0\u884c#include
\n#include int main() {char str[] \\”Hello World\\”;\/\/ \u8f93\u51fa 11（H\u5230d\u517111\u4e2a\u5b57\u7b26，\u4e0d\u542b\\\\0&#<\/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":[55,174,427],"topic":[],"class_list":{"0":"post-62456","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"hentry","6":"category-server","7":"tag-c","9":"tag-427"},"yoast_head":"\n