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Barefootsanders

Nov 15th, 2007 8:26 am

Function syntax to take in a char array and return keyboard input

Hey everyone,

I'm working on function that will take in a char array, prompt the user to input a string, and then return that string to the function. Below is what I've been working on and yes, I know it is not the right syntax, but I'm hoping someone could help me fix it so it works. Thanks!

-Barefoot

char getString(char)



int main() {

    char string[200];

    string = getString(string);

}



char getString(char string) {

    scanf("%s",string);

    return string;

}

Duoas

Nov 15th, 2007 10:05 am

Re: Function syntax to take in a char array and return keyboard input

You are on the right track. The only problem is that char is a single character, not a whole list of them (or array of them). You probably want to use a pointer to an array of chars.

Also, don't use %s in scanf() without qualifying it with a maximum width.

char *getString(char *string);



int main() {

    char string[200];

    getString(string);

}



char *getString(char *string) {

    scanf("%200s",string);

    return string;

}

You can pass the length of the target string into the function if you want:

char *getString( char *string, int length ) {

  char format[ 30 ];

  sprintf( format, "%%%ds", length );

  scanf( format, string );

  return string;

  }

Hope this helps.

Salem

Nov 15th, 2007 10:05 am

Re: Function syntax to take in a char array and return keyboard input

Study the interface which fgets() provides.

Barefootsanders

Nov 15th, 2007 6:07 pm

Re: Function syntax to take in a char array and return keyboard input

Quote:

Originally Posted by Duoas (Post 470380)

char *getString(char *string);



int main() {

    char string[200];

    getString(string);

}



char *getString(char *string) {

    scanf("%200s",string);

    return string;

}

Ahh, thanks. Worked like a charm. Exactly what I needed.

Salem

Nov 15th, 2007 7:08 pm

Re: Function syntax to take in a char array and return keyboard input

> Worked like a charm. Exactly what I needed.
That's a shame, considering that there's a bug in the code.
Let's see if other people can spot it.

Barefootsanders

Nov 15th, 2007 7:20 pm

Re: Function syntax to take in a char array and return keyboard input

Quote:

Originally Posted by Salem (Post 470764)

> Worked like a charm. Exactly what I needed.
That's a shame, considering that there's a bug in the code.
Let's see if other people can spot it.

sorry, I should have said I changed it to this,

char *getString(char *string) {

        scanf("%199s",string);

        return string;

}

to provide for the null char. Thanks again:)

WaltP

Nov 15th, 2007 9:41 pm

Re: Function syntax to take in a char array and return keyboard input

Quote:

Originally Posted by Barefootsanders (Post 470768)

sorry, I should have said I changed it to this,

char *getString(char *string) {

        scanf("%199s",string);

        return string;

}

to provide for the null char. Thanks again:)

We still recommend:

char *getString(char *string) {

        fgets(string, 200,stdio);

        return string;

}

It's just too easy to make a mistake with

scanf()

. And why do you need to pull in the and execute the parsing for %d, %u, %i, %g, etc when

fgets()

requires nothing extra but reading a string. Safely.

Salem

Nov 16th, 2007 4:19 am

Re: Function syntax to take in a char array and return keyboard input

Yet still, the size of the buffer which is being written to isn't being passed as a parameter.
*shrug*

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