#include <iostream>
#include <string.h>

using namespace std;

char* Mystrcpy(char* dst,const char* src)
{
    if(dst == NULL || src == NULL)
        return NULL;
    int i = 0;
    for(i = 0;src[i] != ‘\0‘;i++)
    {
        dst[i] = src[i];
    }
    dst[i] = ‘\0‘;
    return dst;
}
char
 
* Mystrncpy(char *dest, const char *src, size_t n)
{
    if(dest == NULL || src == NULL)
        return NULL;
    int i;
    for (i = 0; i < n && src[i] != ‘\0‘; i++)
      dest[i] = src[i];
    for ( ; i <= n; i++)
        dest[i] = ‘\0‘;

    return dest;
}

int main()
{
    char dst[10];
    
 
char dst1[4];
    char src[] = "hello";
    Mystrcpy(dst,src);
    cout << dst << endl;
    Mystrncpy(dst1,src,3);
    cout << dst1 << endl;
    return 0;
//結果：
/*
hello
hel
*/

自己實現strcpy與strncpy