字符串逆置

#include<stdio.h>
#include<string.h>

void reverseStr(char *str,int len)
{
    char *start = str;
    char *end = str + len -1;
    char ch;
    if(str != NULL)
    {
        while(start < end)
        {
            ch = *start;
            *start++ = *end;
            *end-- = ch;
        }
    }
}

int main()
{
    char str[] = "I love you";
    reverseStr(str,strlen(str));
    printf("%s\n",str);
}