This gist represents my implementation of the itoa function in c.

explanation.md

int to string itoa() function in c

Motivation: I tried once to use the itoa() function in one of my c programs, but it seems that it doesn't work... so I decided to make my own implementation to cast an int into string.

This code was based on various resources, still it is easy to understand and to use. For example:

int main() 
{ 
 char str[100]; 
 printf("the result of itoa: %s", itoa(3267,str,10));
 return 0; 
} 

Itoa.c

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

typedef enum{false, true} bool;

void swap(char *a, char *b)                                                                                                                                                                       
  {
       if(!a || !b)
           return;

       char temp = *(a);
       *(a) = *(b);
       *(b) = temp;
   }

void reverse(char *str, int length) 
{ 
	int start = 0; 
	int end = length -1; 
	while (start < end) 
	{ 
		swap((str+start), (str+end)); 
		start++; 
		end--; 
	} 
} 

char* itoa(int num, char* str, int base) 
{ 
	int i = 0; 
	bool isNegative = false; 

	if (num == 0) 
	{ 
		str[i++] = '0'; 
		str[i] = '\0'; 
		return str; 
	}

	if (num < 0 && base == 10) 
	{ 
		isNegative = true;
		num = -num; 
	} 

	while (num != 0) 
	{ 
		int rem = num % base; 
		str[i++] = (rem > 9)? (rem-10) + 'a' : rem + '0'; 
		num = num/base; 
	}

	if (isNegative == true) 
		str[i++] = '-'; 

	str[i] = '\0';
	reverse(str, i); 
	return str; 
}