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
