How to Convert an Integer to a String in C?

Last Updated : 21 May, 2025

In C, integers can be represented as strings with each digit represented by corresponding numeric character. In this article, we will learn how to convert integers into the string

Examples

Input: 1234
Output: "1234"
Explanation: The integer 1234 is converted to the string "1234".
Input: -567
Output: "-567"
Explanation: The integer -567 is converted to the string "-567".

There are various methods that can be used to convert integer to a string in C:

Manual Conversion Using Loop

We can convert an integer to a string manually by extracting each digit one by one and converting it to its corresponding character by using their ASCII code and storing it in the character array to form a string.

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

void intToStr(int N, char *str) {
    int i = 0;
  
    // Save the copy of the number for sign
    int sign = N;

    // If the number is negative, make it positive
    if (N < 0)
        N = -N;

    // Extract digits from the number and add them to the
    // string
    while (N > 0) {
      
        // Convert integer digit to character and store
      	// it in the str
        str[i++] = N % 10 + '0';
      	N /= 10;
    } 

    // If the number was negative, add a minus sign to the
    // string
    if (sign < 0) {
        str[i++] = '-';
    }

    // Null-terminate the string
    str[i] = '\0';

    // Reverse the string to get the correct order
    for (int j = 0, k = i - 1; j < k; j++, k--) {
        char temp = str[j];
        str[j] = str[k];
        str[k] = temp;
    }
}

int main() {
    int N = 1234;
    char str[12];

    intToStr(N, str);

    printf("String: %s\n", str);

    return 0;
}

Output

String: 1234

Using sprintf() Function

We can also use the sprintf function in C to convert an integer to a string. The working of sprintf() function is similar is similar to printf() but instead of printing the output it stores the formatted output into a character array(string buffer).

#include <stdio.h>

int main() {
  
    // Integer to be converted
    int N = 86;

    // Buffer to hold the resulting string
    char str[20];

    // Converting integer to string using sprintf
    sprintf(str, "%d", N);

    printf("The integer %d converted to string is: %s\n",
           N, str);

    return 0;
}

Output

The integer 86 converted to string is: 86

Note: We can also use the snprintf function which is similar to sprintf but with a buffer size limit, which helps prevent buffer overflows.

Using itoa() Function

itoa() is a non-standard function available in some C compilers like MSVC, etc. It stands for Integer TO ASCII. It converts the given integer value to a null-terminated string and stores the result in the character array( buffer) defined by string parameter.