Problem with itoa converting integer to string

Question

Perhaps not a really important question, but just starting out in c. Why will this not compile correctly?

#include <stdio.h>
#include <stdlib.h>

void main()
{
int i = 15;
char word[100];

itoa (i,word,10);

printf("After conversion, int i = %d, char word = %s", i, word);
}

I keep getting the error message

Undefined symbols:
"_itoa", referenced from:
_main in ccubsVbJ.o
ld: symbol(s) not found
collect2: ld returned 1 exit status

It's a non-standard function, and may not be included with your stdlib.h. see wikipedia, http://en.wikipedia.org/wiki/Itoa — thelaws, Apr 07 '11 at 01:57
Define your main as `int main()`. More here : http://stackoverflow.com/questions/636829/difference-between-void-main-and-int-main — , Apr 07 '11 at 01:58

GWW · Accepted Answer · 2011-04-07T02:16:45.327

6

Use sprintf instead, itoa is not part of the C standard and it's probably not included in your stdlib implementation.

sprintf(word,"%d",i);

UPDATE:

As noted in the comments snprintf is safer to use to avoid buffer overflows. In this case it's not necessary because your buffer is longer than the largest integer that can be stored in a 32-bit (or 64-bit integer). But it's good to keep buffer overflows in mind.

edited Apr 07 '11 at 02:16

answered Apr 07 '11 at 01:55

GWW

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2

If available you should be using **snprintf()** to avoid buffer overflows. – Ben Apr 07 '11 at 02:06
1

+1, although snprintf would be better due to potential buffer overflows with sprintf (won't happen here though). – David X Apr 07 '11 at 02:09
1

I agree that snprintf is better if you can buffer overflow. – GWW Apr 07 '11 at 02:11

score 2 · Answer 2 · answered Apr 07 '11 at 01:54

2

itoa is a non-standard function, it may not be included in your implementation. Use something like sprintf instead.

answered Apr 07 '11 at 01:54

jonsca

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Problem with itoa converting integer to string

2 Answers2