C Input Output (I/O)

• Tech Area
• Last updated on: January 8, 2026

In this tutorial, We will see the example of input and output function in C programming language.

C Output

In C programming, printf() is one of the main output function.

Example: C Output

#include<stdio.h>
void main()
{
printf("C Example");  //Displays the string
}

Output

C Example

How does this program work?

To use printf() in our program, we need to include stdio.h header file using the #include <stdio.h> statement.

All valid C programs must contain the main() function. The code execution begins from the start of the main() function.

The printf() is a library function to send formatted output to the screen. The function prints the string inside quotations.

C Input

In C programming, scanf() is one of the commonly used function to take input from the user.

Example: C Input

#include<stdio.h>
void main()
{
    int number;
    printf("Enter a number: ");
    scanf("%d", &number);  
    printf("Number = %d",number);
}

Output

Enter a number: 10
Number = 10

Here, we have used %d format specifier inside the scanf() function to take int input from the user. When the user enters an integer, it is stored in the number variable.