In C programming we take input and print result based on that or whatever we want to .

For doing input or output process C library has provided functions for doing it.

The getchar() and putchar() Functions

The getchar function is used to take characters from the string one by one by loop iteration.

The putchar function is used to display string in the form of characters one by one by using loop iteration

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

   int c;

   printf( "Enter a value :");
   c = getchar( );

   printf( "\nYou entered: ");
   putchar( c );

   return 0;
}

The gets() and puts() Functions

The gets function is used to take input from the keyboard in string format.

The puts function is used to display string.

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

   char str[100];

   printf( "Enter a value :");
   gets( str );

   printf( "\nYou entered: ");
   puts( str );

   return 0;
}

The scanf() and printf() Functions

The scanf function is used to take input from the user.

The printf function is used to display output by the program or to the user

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

   char str[100];
   int i;

   printf( "Enter a value :");
   scanf("%s %d", str, &i);

   printf( "\nYou entered: %s %d ", str, i);

   return 0;
}