Question: The strchr function

hey guys , this is the strchr function , i was wondering what does that return at the end of the code do ? i can't really understand it , what does the '?' sign do ?

Code:

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#include <string.h>
 /* strchr */
 char *(strchr)(const char *s, int c)
 {
    while (*s != '\0' && *s != (char)c)
        s++;
    return ( (*s == c) ? (char *) s : NULL );
 }

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could someone put a main function in the code so i can trace it and try to get it myself ?

Quote:

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Originally Posted by everyone0

what does that return at the end of the code do ? i can't really understand it , what does the '?' sign do ?

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Basically, it is another way of saying:

Code:

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if (*s == c)
{
    return (char *) s;
}
else
{
    return NULL;
}

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mm thanks , the instructor definitely did not tell me that :)

giving me an expected error

Code:

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#include <string.h>
#include <stdio.h>
#include <conio.h>
 void strchr(*s, char c)
 {
    while (*s != '\0' && *s != (char)c)
        s++;
    return ( (*s == c) ? (char *) s : NULL );
 }
 main()
 {
 char s[5],c;
 scanf("%s",&s);
 strchr(&s,c);
 printf("%s",s);
 getch();
 }

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Why did you change from char* to void?

still same problem when i turned it back to char*

Quote:

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strchr(*s, char c)

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Where do you specify the type for s? I don't understand your problem. You posted the correct code at the very beginning of this thread and now you're having trouble replicating it? Are you just not paying attention or what? Are you even trying?

Quote:

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Gawking at stupidity

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If you don't stop that, your face is going to get frozen that way! :)

well i corrected the code as u said but now it says ambiguity between the function and the way im calling it

Code:

---

#include <string.h>
#include <stdio.h>
#include <conio.h>
 char *(strchr)(const char *s, char c)
 {
    while (*s != '\0' && *s != (char)c)
        s++;
    return ( (*s == c) ? (char *) s : NULL );
 }
 main()
 {
 char s[5],c;
 scanf("%s",&s);
 strchr(s,c);
 printf("%s",s);
 getch();
 }

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That's because there's already a prototype for a strchr function in string.h, which you're #including. Change the name of your implementation to my_strchr, or fake_strchr, or something instead to avoid the conflict.

Refer to your notes on the correct way to use scanf to read a string.

wow i feel stupid! thanks for the help