教你如何自己实现字符串操作

1、char dest[128] = {'\0'}; char *src = "this is a test"; mystrcpy(dest,src); puts(dest);

2、char dest1[128] = {'\0'}; char *src1 = "this is a test"; mystrncpy(dest1,src1,4); puts(dest1);

3、char dest1[128] = {'\0'}; char *src1 = "this is a test"; mystrncpy(dest1,src1,4); puts(dest1);

4、char *mystrcpy(char* dest, const char *src)//const是一个C语言（ANSI C）的关键字，具有着举足轻重的地位。它覆诈端螽限定一个变量不允许被改变，产生静态作用。{ if(dest == NULL || src == NULL){ return NULL; }

5、 while(*src != '\0'){ *dest ++ = *src++; } *dest = '\0'; return dest;}

6、char *mystrncpy(char* dest1, const char *src1,int n){ if(dest1== NULL || src1 == NULL){ return NULL; }

7、while(*src1 != '\0'&&n>0){ *dest1 ++ = *src1++; n--; } *dest1 = '\0'; return dest1;}

8、运行程序