package demo.lang; public class Rectangle { public int sideA; public int sideB; public Rectangle(int x, int y) { super(); sideA = x; sideB = y; } public boolean equals(Object obj) { if(!(obj instanceof Rectangle)) return false; Rectangle ref = (Rectangle)obj; return (((this.sideA==ref.sideA)&&(this.sideB==ref.sideB))|| (this.sideA==ref.sideB)&&(this.sideB==ref.sideA)); } public static void main(String[] args) { Rectangle r1 = new Rectangle(10,20); Rectangle r2 = new Rectangle(10,10); Rectangle r3 = new Rectangle(20,10); System.out.println("r1.equals(r1) == " + r1.equals(r1)); System.out.println("r1.equals(r2) == " + r1.equals(r2)); System.out.println("r1.equals(r3) == " + r1.equals(r3)); System.out.println("r2.equals(r3) == " + r2.equals(r3)); System.out.println("r1.equals(null) == " + r1.equals(null)); } } |