Saturday 17 January 2015

A Java Class with a Method

A Java class can have a method. This is a piece of code which can be used on members of the class. In the example below, a class called Square is created. The Square class has a method called display_area, which calculates and displays the area of the square: 

andrew@UBUNTU:~/Java$ cat Square.java
public class Square
  {
  double width;
  double area;
  public void display_area()
    {
    area = width * width;
    System.out.println("Area = " + area);
    }
  }
class SquareExample
  {
  public static void main(String args[])
    {
    Square my_square = new Square();
    my_square.width = 5;
    my_square.display_area();
    }
  }
andrew@UBUNTU:~/Java$ javac Square.java
andrew@UBUNTU:~/Java$ java SquareExample
Area = 25.0
andrew@UBUNTU:~/Java$