Page 114 - ComputerScience_Class_11

21 }
22 public static void main(String[] args)

23 {
24 rectangle obj = new rectangle();
25 obj.assign();

26 obj.cal_area();

27 obj.cal_perimeter();
28 obj.display();
29 }

30 }

What does the above code mean?
1. In the above program, an object is being created. The name of the object is “obj”. The line that is used to create the
object is “rectangle obj = new rectangle();”.
2. After creating the object, the assign() method is invoked and the data members length and breadth are assigned
with the values 5 and 2 respectively.
3. Then, the cal_area() method is executed to calculate the area of the rectangle. The calculated value is assigned to
the data member “area”.
4. After that, the calculation of the perimeter is done by invoking the cal_perimeter() method and the result is stored
in the “perimeter” data member.
5. And at the end of the execution of the program, the display() method is invoked to display the calculated area and
the perimeter of the rectangle.
The output of the preceding program is as follows:

BlueJ: Terminal Window - Java

Options
Area : 10 cm
Perimeter : 14 cm

Let’s consider another example:

Program 2 Write a program to store and display student details, including their marks in Computer and
Mathematics and calculate the average marks and total marks for each student.

1 import java.util.*;
2 class student

3 {
4 String name;

5 int roll_no, comp_m, math_m, total_m;
6 student()

7 {
8 name="";

112 Touchpad Computer Science (Ver. 3.0)-XI