for (i = 0; i<(strlen(arr1)+1)/2; i++)
只需将循环中的"i"在定义时定义为无符号即可，即unsigned i;
产生错误的代码：
#include<stdio.h>
#include<stdlib.h>
#include<string.h>
int main()
{
char arr1[] = { "Welcome to bit!" };
int num = strlen(arr1);
unsigned i;
char arr2[20] = {"***************"};
printf("%s\n", arr2);
for (i = 0; i<(strlen(arr1)+1)/2; i++)
{
arr2[i] = arr1[i];
arr2[strlen(arr1) - i - 1] = arr1[strlen(arr1) - i - 1];
printf("%s\n",arr2);
}
system("pause");
return 0;
}原文地址：http://10739786.blog.51cto.com/10729786/1701505
