This example is based on an earlier post but I have changed it to show how a method can return a value. The first part creates a class called Square:
andrew@UBUNTU:~/Java$ cat Square.java
public class Square
{
double width;
public void display_area()
{
// The next line calls the calculate_area method.
// The value returned is assigned to area:
double area = calculate_area();
System.out.println("Area = " + area);
}
// The word double in the next line tells you
// that this method returns a double value:
private double calculate_area()
{
double area = width * width;
// The next line returns the value:
return area;
}
}
andrew@UBUNTU:~/Java$ javac Square.java
andrew@UBUNTU:~/Java$
The second part creates a member of the Square class and calls the methods which calculate and display its area:
andrew@UBUNTU:~/Java$ cat SquareExample.java
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 SquareExample.java
andrew@UBUNTU:~/Java$ java SquareExample
Area = 25.0
andrew@UBUNTU:~/Java$
