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How to Convert an Integer to a String in C?

Last Updated : 23 Jul, 2025
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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.

C 
#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).

C 
#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.

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

int main() {
    int N = 1234;
  
    // Declare a character array 'str' t store the converted
    // string
    char str[12];

    // Calling itoa()
    itoa(N, str, 10);

    printf("String: %s\n", str);
    return 0;
}


Output

String: 1234

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