原创 memcpy()与strcpy()的完全实现

int main()
{
    char* a = "he\0llo";
    char b[10];
 memcpy(b,a,10);
 for(int k=0;k<6;k++)
  cout << b[k] <<endl;
    return 0;
}
输出：
h
e

l
l
o
=================================
strcpy()的实现。
char* strcpy(char* dest,const char* source)
{
     assert(dest!=NULL&&source!=NULL);
     while((*dest++ = *source++) != '\0')
                            ;
     return dest;
}
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可用一下函数来观察memcpy()与strcpy()的区别
#include <string.h>
#include <stdio.h>

int main()
{
    char a[30] = "string (a)";
    char b[30] = "hi\0zengxiaolong";
    int i;

    strcpy(a, b);             //a[30] = "hi\0ing (a)"
    printf("strcpy():");
    for(i = 0; i < 30; i++)
        printf("%c", a);   //hiing (a)


    memcpy(a, b, 30);         //a[30] = "hi\0zengxiaolong"
    printf("\nmemcpy():");
    for(i = 0; i < 30; i++)
        printf("%c", a);   //hizengxiaolong
    printf("\n i = %d\n", i); //30

}