Program 5.1: A Test for String Equality

<, >, <= and >= can only be used with numbers and characters. They cannot be used with Strings, booleans, arrays or other compound types since there's no well-defined notion of order for these objects. Is true greater than false? Is "My only regret is that I have but one life to give for my country" greater than "I have a dream""

Equality is a little easier to test however. true is equal to true and true is not equal to false. Similarly "My only regret is that I have but one life to give for my country" is not equal to "I have a dream." However you might be surprised if you ran Program 5.1.

class JackandJill {

  public static void main(String args[]) {
  
    String s1 = "Jack went up the hill.";
    String s2 = "Jack went up the hill.";
    
    if (s1 == s2) {
      System.out.println(
        "The strings are the same.");
    }
    else if (s1 != s2) {
      System.out.println(
        "The strings are different.");
    }
  
  }

}

The strings are different.