/*
 *  File: TestStringEquals.java
 *  Author: Java, Java, Java
 *  Description: This program illustrates the differences
 *   between the == operator and the equals() method as
 *   applied to String objects.  The == operator implements
 *   string identity, where two string references are identical if
 *   they refer to the same object. The equals() method 
 *   implements string equality, where two strings are equal
 *   if they contain the same characters in the same order.
 */

import java.awt.*;

public class TestStringEquals {
    static String s1 = new String("hello");  // s1 and s2 are equal, not identical
    static String s2 = new String("hello");
    static String s3 = new String("Hello");  // s1 and s3 are not equal
    static String s4 = s1;                   // s1 and s4 are identical
    static String s5 = "hello";              // s1 and s5 are not identical
    static String s6 = "hello";              // s5 and s6 are identical

    private static void testEqual(String str1, String str2) {
        if (str1.equals(str2))
            System.out.println(str1 + " equals " + str2);
        else
            System.out.println(str1 + " does not equal " + str2);
    } // testEqual()

    private static void testIdentical( String str1, String str2 ) {
        if (str1 == str2)
            System.out.println(str1 + " is identical to " + str2);
        else
            System.out.println(str1 + " is not identical to " + str2);
    } // testIdentical()

    public static void main(String argv[]) {
        testEqual(s1, s2);        // equal
        testEqual(s1, s3);        // not equal
        testEqual(s1, s4);        // equal
        testEqual(s1, s5);        // equal
        testEqual(s5, s6);        // equal

        testIdentical(s1, s2);    // not identical
        testIdentical(s1, s3);    // not identical
        testIdentical(s1, s4);    // identical
        testIdentical(s1, s5);    // not identical
        testIdentical(s5, s6);    // identical
    } // main()
}// TestStringEquals