将字符串s2复制到s1中
#include <stdio.h>
int main()
{
char s1[20]="How are you", s2[5]="what";
puts(s1);
for (int i=0; i<5; s1[i++]=s2[i]);
puts(s1);
return 0;
}
//s1[i++]=s2[i])这句表示理解不了