C Input / Output

C programming has several in-built functions to perform input and output tasks.

Two commonly used functions for I/O (Input/Output) are printf() and scanf().

printf() and scanf() functions are inbuilt functions in C programming environment which are available in C library by default. These functions are declared and related with “stdio.h” which is a header file in C language.

printf() method in C :

printf() function sends formatted output to the standard output(screen). printf() is used to show any message or value of any data type.

We use printf() function with %d format specifier to display the value of an integer variable. Similarly %c is used to display character, %f for float variable, %s for string variable, %lf for double and %x for hexadecimal variable.

To generate a newline,we use “\n” in C printf() statement.

Example 1 :

#include <stdio.h>      //This is needed to run printf() function.
int main()
{
    printf("C Programming");     //displays the content inside quotation
    return 0;
} 

Output :

C Programming

Example 2 :

#include<stdio.h>
int main()
{
     int a = 5, b = 7;
     printf("Value of a = %d \n, a);
     printf("Value of b = %d, b);
     return 0;
}

Output :

Value of a = 5
Value of b =7 

scanf() method in C :

 scanf() function is used to read character, string, numeric data from keyboard.

Syntax :

scanf ("control string", &variable_name);

Example :

#include <stdio.h>

int main()

{

   char ch;

   char str[100];

   printf("Enter any character :\n");

   scanf("%c", &ch);

   printf("Entered character is %c \n", ch);

   printf("Enter any string : \n");

   scanf("%s", &str);

   printf("Entered string is %s \n", str);

}

Output :

Enter any character :
k
Entered character is k
Enter any string :
hello
Entered string is hello