sprintf() in C

Last Updated : 10 Jan, 2025

Syntax:

int sprintf(char *str, const char *string,...);

Return:

If successful,
it returns the total number of 
characters written excluding 
null-character appended in the string, 
in case of failure a negative number 
is returned .

sprintf stands for “String print”. Instead of printing on console, it store output on char buffer which are specified in sprintf.

// Example program to demonstrate sprintf()
#include <stdio.h>
int main()
{
    char buffer[50];
    int a = 10, b = 20, c;
    c = a + b;
    sprintf(buffer, "Sum of %d and %d is %d", a, b, c);

    // The string "sum of 10 and 20 is 30" is stored
    // into buffer instead of printing on stdout
    printf("%s", buffer);

    return 0;
}

Output

Sum of 10 and 20 is 30

Time Complexity: O(n), where n is the number of elements being stored in buffer.
Auxiliary Space: O(n), where n is the number of elements being stored in buffer.