public class TestCircles
2: import java.util.Scanner;
4: /**
5: * A program to demonstrate the equals method using the Circle class.
6: *
7: * @author Mark Young (A00000000)
8: */
9: public class TestCircles {
11: public static void main(String[] args) {
12: // Create variables
13: Circle c1, c2, c3;
14: String c2String;
15: Object other = null;
16: Circle c5 = null;
18: // Introduce yourself
19: System.out.println("I report on equality of circles!");
20: System.out.println();
21: System.out.println("NOTE: I expect to crash "
22: + "with a NullPointerException!");
23: pause();
25: // Calculate results
26: c1 = new Circle(10.0);
27: c2 = new Circle(5.5);
28: c3 = new Circle(5.5);
29: c2String = c2.toString();
31: // Report results
32: System.out.println(c1 + " == " + c2 + " is " + (c1 == c2));
33: System.out.println(c1 + " == " + c3 + " is " + (c1 == c3));
34: System.out.println(c2 + " == " + c3 + " is " + (c2 == c3));
35: pause();
36: System.out.println(c1 + ".equals(" + c2 + ") is " + c1.equals(c2));
37: System.out.println(c1 + ".equals(" + c3 + ") is " + c1.equals(c3));
38: System.out.println(c2 + ".equals(" + c3 + ") is " + c2.equals(c3));
39: pause();
40: System.out.println(c2 + ".equals(\"" + c2String + "\") is "
41: + c2.equals(c2String));
42: System.out.println(c2 + ".equals(" + other + ") is "
43: + c2.equals(other));
44: System.out.println(c2 + ".equals(" + c5 + ") is " + c2.equals(c5));
45: System.out.println("...about to crash...");
46: System.out.println(c5 + ".equals(" + other + ") is "
47: // NOTE: this will CRASH the program -- that's expected
48: + c5.equals(other));
49: }
50:
51: private static final Scanner KBD = new Scanner(System.in);
53: /**
54: * Prompt the user and wait for them to press the enter key
55: */
56: private static void pause() {
57: System.out.println();
58: System.out.print("...press enter...");
59: KBD.nextLine();
60: System.out.println();
61: }
63: }