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