Default function parameters in C

Question

I'm trying to make a indexOf function in C. The function must find the position of any letter OR word which given in parameters. But when i tried to use one them, the compiler would alert as "too few arguments". How can i do that? Thanks.

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

int indexOf(char*, char*, char);

int main(){
    char stuff[] = "abcdefghijklmopqrstuvwxyz";

    printf("Result: %d", indexOf(stuff, 'b') );
    printf("Result: %d", indexOf(stuff, "defg") );

    getch();
    return 0;
}

int indexOf(char *text, char *word, char letter){
    if(word == DEFAULT VALUE)
        // find the letter in the text
    else if(letter == DEFAULT VALUE)
        // find the word in the text
}

score 5 · Accepted Answer · edited Oct 16 '13 at 12:09

5

You cannot do that in C: the language does not support overloads or default parameters. The only thing that you can do to emulate this would be using variable number of parameters, but that would not work here, because you would need to pass an additional parameter indicating the type of the item being searched.

A better approach would be defining two functions

int indexOfChar(char *text, char letter)
int indexOfWord(char *text, char *wors)

or better yet, using the corresponding functions from the standard library - strchr and strstr.

edited Oct 16 '13 at 12:09

answered Apr 22 '13 at 17:39

Sergey Kalinichenko

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Oh dear, I just noticed you proposed exactly the same solution a few seconds before me - it must be the right thing to do :) – piokuc Apr 22 '13 at 17:43
@piokuc That's funny - even the function names came out the same :) – Sergey Kalinichenko Apr 22 '13 at 17:45

score 4 · Answer 2 · answered Apr 22 '13 at 17:38

4

There is no such thing as default function parameters in C. C++ has the feature, but not C.

In your case I would define two functions instead of one indexOf: indexOfWord and indexOfChar.

answered Apr 22 '13 at 17:38

piokuc

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Default function parameters in C

2 Answers2