hash code overriding in java

Question

I am writing simple code by overriding hashcode and equels method can any one plz expline me how that will work exactly if i overried or not overried in my class.

class HexToDec {
      public static void main(String[] args) {
            Test t = new Test();
    //        Test t1 = new Test("Aamir", true, "good lead, choclate hero");
            Test t3 = new Test();
            Test t4 = new Test();
            t4.setName("ranjith");
            System.out.println("a1.hashCode() = " + t);
            System.out.println("a2.hashCode() = " + t4);
            System.out.println("a1.hashCode() = " + t3.hashCode());
            System.out.println("a2.hashCode() = " + t4.hashCode());
    //        System.out.println("is a1 == a2 " + (t == t1));
            System.out.println("is a1.equals(a2) " + (t3.equals(t4)));
        }
    }

http://stackoverflow.com/questions/27581/overriding-equals-and-hashcode-in-java — stinepike, Dec 31 '13 at 06:36
http://javapapers.com/core-java/hashcode-and-equals-methods-override/ — Jagadesh Seeram, Dec 31 '13 at 06:37

TheLostMind · Answer 1 · 2013-12-31T06:55:43.613

-1

you have to override hashCode() method whenever you override equals(). because, hashcode is used to uniquely identify each object. If 2 objects are equal, then they should be having the same hashcode. Once you change the equals() method, you override hashCode() to make it understand on what grounds two objects can be considered equal.

http://javapapers.com/core-java/hashcode-and-equals-methods-override/

edited Dec 31 '13 at 06:55

answered Dec 31 '13 at 06:38

TheLostMind

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if call override equals() method hashcode method has to call right. – Venkatarama reddy Dec 31 '13 at 06:43
1

Object class had a default implementation for hashcode method [default implementation](http://docs.oracle.com/javase/7/docs/api/java/lang/Object.html#hashCode()) – Srinath Ganesh Dec 31 '13 at 06:48
http://stackoverflow.com/questions/2265503/why-do-i-need-to-override-the-equals-and-hashcode-methods-in-java – TheLostMind Dec 31 '13 at 06:49
@Venkataramareddy - I am not getting you... – TheLostMind Dec 31 '13 at 06:56
@SrinathGanesh - Object class "still has" a default implementation of hashCode() , but how is that relevant to this question?. Its a mere statement. – TheLostMind Dec 31 '13 at 06:57

hash code overriding in java

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