Functions printf() and scanf() in C

The printf() and scanf() functions are the most commonly used functions in C Programming. These functions are widely used in majority of the C programs. In this tutorial, you will learn, what are these functions, how to use them in C Program.

The scanf() and printf() functions are used for input and output in c programs receptively. These functions are defined in stdio.h header file, so you must include this header file in your program, if you are using any of these functions.

printf() function:

The prinf() function is used to display (or print) output on the console screen.

Syntax of printf() function:

printf("format string",arguments);

The format string (or format specifier) is a string that is used for formatting the input and output. Format string always starts with a ‘%’ character. For example format string for integer is %d, for string %s, for float %f and so on.

scanf() function:

The scanf() function is used to read the input entered by user.

Syntax of scanf() function:

scanf("format string",arguments);

Example 1: use printf() and scanf() functions to add two input numbers

In the following example, we are calculating the sum of two user entered numbers. Program prints message on console to enter the numbers using printf(). The input numbers are read and stored in the variables num1 and num2 by scanf() function. After the sum is calculated, the result is displayed on console using printf() function.

#include<stdio.h>
int main(){

  int num1,num2,sum;
  printf("Enter first number: ");
  scanf("%d",&num1);
  printf("Enter second number: ");
  scanf("%d",&num2);
  sum=num1+num2;
  printf("Sum of %d and %d is: %d ",num1, num2, sum);
  return 0;
}