[c] How to convert an integer to a character array using C

I want to convert an integer number to a character array in C.

Input:

int num = 221234;

The result is equivalent to:

char arr[6];
arr[0] = '2';
arr[1] = '2';
arr[2] = '1';
arr[3] = '2';
arr[4] = '3';
arr[5] = '4';

How can I do this?

You may give a shot at using itoa. Another alternative is to use sprintf.

The easy way is by using sprintf. I know others have suggested itoa, but a) it isn't part of the standard library, and b) sprintf gives you formatting options that itoa doesn't.

'sprintf' will work fine, if your first argument is a pointer to a character (a pointer to a character is an array in 'c'), you'll have to make sure you have enough space for all the digits and a terminating '\0'. For example, If an integer uses 32 bits, it has up to 10 decimal digits. So your code should look like:

int i;
char s[11]; 
...
sprintf(s,"%ld", i);

Use itoa, as is shown here.

char buf[5];
// Convert 123 to string [buf]
itoa(123, buf, 10);

buf will be a string array as you documented. You might need to increase the size of the buffer.