scanf() Function

How to Read Data From Keyboard Using scanf() Function

Similar to printf() function, scanf() function also uses the %d,  %f,  %c  and other format specifiers to specify the kind of data to be read from the keyboard.

However, it expects the programmer to prefix the address operator  '&'  to every variable written in the argument list as show below:

int roll;

scanf("%d",$roll);

The above set of statements declares the variable 'roll' of data type 'int', and reads the value for 'roll' from the keyboard. It may be noted that  '&'  the address operator, is prefixed to the variable  'roll'. The reason for specifying  '&'  would be discussed later.

Similarly, other format specifiers can be to input data from the keyboard.

Example 1: Write an interactive program that reads the marks secured by a student for four subjects  'Sub1', 'Sub2', 'Sub3' and  'Sub4' the maximum marks of a subject being 100. The program shall compute the percentage of marks obtained by the student.

Solution : The scanf()  and  printf()  functions would be used to do the required task. The required program is as follows :

#include<stdio.h>

main()

{

int sub1,sub2,sub3,sub4;

float percent;

printf("Enter the marks for four subjects :");

scanf("%d %d %d %d", &sub1, &sub2, &sub3, &sub4);

percent = (sub1 + sub2 + sub3 + sub4)/400.00*100;

printf("The percentage = %f", & percent);

}

For input data :  45  56  76  90  

The above program computes the percentage and displays the following output :

Outout :

The percentage = 66.750000