C Input output function

C programming language provides many of the built-in functions to read given input and write data on screen, printer or in any file.

1 scanf() and printf() functions

#include<stdio.h>
#include<conio.h>
void main()
{
 int i;
 printf("Enter any value");
 scanf("%d",&i);
 printf( "\nYou entered:= %d",i);
 getch();
}

When you will compile the above code, it will ask you to enter a value. When you will enter the value  , it will display the value you have entered.

2 getchar() & putchar() functions

#include <stdio.h>
#include <conio.h>
void main( )
{
 int m;
 printf("Enter a character");
 m=getchar();
 putchar(m);
 getch();
}

The getchar() function reads a character from the terminal and returns it as an integer. This function reads only single character at a time. You can use this method in the loop in case you want to read more than one characters. The putchar() function prints the character passed to it on the screen and returns the same character. This function puts only single character at a time. In case you want to display more than one characters, use putchar() method in the loop.
When you will compile the above code,it will ask you to enter a value. When you will enter the value, it will display the value you have entered.

3 gets() & puts() functions

#include<stdio.h>
#include<conio.h>
void main()
{
 char s[100];
 printf("Enter any string");
 gets(s);
 puts(s);
 getch();
}

The gets() function reads a line from stdin into the buffer pointed to by s until either a terminating newline or EOF (end of file). The puts() function writes the string s and a trailing newline to stdout.
When you will compile the above code,it will ask you to enter a string. When you will enter the string, it will display the value you have entered.