C语言 strchr 函数用法

#include <stdio.h>

#include <string.h>

int main ()

{

   const char str[] = "http://www.runoob.com";

   const char ch = '.';

   char *ret;

   ret = strchr(str, ch);

   printf("|%c| 之后的字符串是 - |%s|\n", ch, ret);

   return(0);

}

|.| 之后的字符串是 - |.runoob.com|

//#define  FIRST_DEMO

#define  SECOND_DEMO

#ifdef FIRST_DEMO

#include <stdio.h>

#include <conio.h>

#include <string.h>

#pragma warning (disable:4996)

int main(void)

{

    char string[17];

    char *ptr;

    char c='T';

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

    ptr=strchr(string,c);

    if (ptr)

    {

        printf("The character %c is at position:%d\n",c,ptr-string);

    }

    else

    {

        printf("The character was not found\n");

    }

    getch();

    return 0;

}

#elif defined SECOND_DEMO

#include <stdio.h>

#include <conio.h>

#include <string.h>

#pragma warning (disable:4996)

int main(void)

{

    char answer[100];

    char *p;

    printf("Type something:\n");

    fgets(answer,sizeof answer,stdin);

    if ((p=strchr(answer,'\n'))!=NULL)   /*fgets不会像gets那样自动地去掉结尾的\n，所以程序中手动将\n位置处的值变为\0,代表输入的结束。*/

    {

        *p='\0';

    }

    printf("You typed \"%s\"\n",answer);

    getch();

    return 0;

}

#endif