C 语言中strstr函数实例详解
strstr函数
strstr(str1,str2) 函数用于判断字符串str2是否是str1的子串。如果是，则该函数返回str2在str1中首次出现的地址；否则，返回NULL
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const char* strstr(const char* str1,const char* str2);char* strstr(char* str1,const char* str2); |
库中实现的strstr
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#include <stdio.h> #include <string.h> int main () { char str[] ="This is a simple string"; char * pch; pch = strstr (str,"simple"); strncpy (pch,"sample",6); puts (str); return 0; } |
模拟实现strstr函数
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const char* My_strstr(const char* str1, const char* str2) { assert(str1); assert(str2); while (*str1 != '\0') { const char* p1 = str1; const char* p2 = str2; while ((*p1 != '\0') && (*p2 != '\0') && (*p1 == *p2)) { ++p1; ++p2; } if (*p2 == '\0') { return str1; } ++str1; } return NULL; } int main() { char str1[] = "a wwww qqqqqqqqqqqqqqq"; char str2[] = "www"; printf("%s\n", My_strstr(str1, str2)); system("pause"); return 0; } |
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原文链接：http://blog.csdn.net/weixin_36125166/article/details/74025182
