请帮忙看一下这段代码哪有问题，谢谢
#include<stdio.h>
void main(void)
{
    void copy(char a[], char b[]);
    char c[] = "I love china", d[20];
    copy(c, d);
    printf("string a is=%s\n", c);
    printf("string b is=%s\n", d);

}
void copy(char a[], char b[])
{
    int i;
    for (i = 0; a[i] != "\0"; i++)
        b[i] = a[i];
    b[i] = "\0";
}

谢谢，我刚把"\0",改为'\0'就对了