100分请教 strrchr ！

[castlooo]

int main(int argc, char* argv[])
{
    char string[15];
   char *ptr, c = 'r';

   strcpy(string, "This is a string");
   ptr = strrchr(string, c); // ptr
   if (ptr)
      printf("The character %c is at position: %d\n", c, ptr-string);
   else
      printf("The character was not found\n");
   return 0;
    //The character g is at position: 15

}

帮忙分析下，为什么结果为
The character g is at position: 15
不是找 'r'么 怎么打出来是g？

[yyyapple]

重新构建一下代码，没问题的

[netlib]

我试了一下，我这里返回是12。

char string[15];
char *ptr, c = 'r';

strcpy(string, "This is a string");

这里有溢出，长度超了

[wangdeqie]

//是正确的
#include <stdio.h>
#include <string.h>
int main(int argc, char* argv[])
{
    char string[15];
	char *ptr, c = 'r';
	
	strcpy(string, "This is a string");
	ptr = strrchr(string, c); // ptr
	if (ptr)
		printf("The character %c is at position: %d\n", c, ptr-string);
	else
		printf("The character was not found\n");
	return 0;
    //The character g is at position: 15
	
}
//VC6下运行结果：
The character r is at position: 12
Press any key to continue

[guzhilei1986]

o也试了一下，没有问题的。

[珍惜生命远离CPP]

注意，越界了
char string[15];
改为
char string[32];

[castlooo]

bcb 6.0
//---------------------------------------------------------------------------

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

//---------------------------------------------------------------------------

#pragma argsused
int main(int argc, char* argv[])
{
char string[15];
char *ptr, c = 'r';

strcpy(string, "This is a string");
ptr = strrchr(string, c);
if (ptr)
printf("The character %c is at position: %d\n", c, ptr-string);
else
printf("The character was not found\n");
return 0;
}
//---------------------------------------------------------------------------
// 结果 The character g is at position: 15

[yyyapple]

最有可能是数组越界把"This is a string" 覆盖了变量c的'r'

[wangdeqie]

如果还不行，改成char string[20];

[yyyapple]

数组尺寸换大点吧

[tangyulong1214]

char string[15];
char *ptr, c = 'r';

strcpy(string, "This is a string");

"This is a string"这个字符串需要超过15个长度的数组来存储！！！

是新手吧？

[castlooo]

字符长度为 16
是越界了
改为16 也没问题了

[castlooo]

是新手 又咋地?

[wangdeqie]

细心点就好了 ^_^

[LUCI-Z]

谁都是新手过来的把
慢慢学都会厉害的

[Cf251Suzsoft]

數組越界