What is the difference between equales and ==

Question

I am new to java, and i was wondering what is the difference between equales and ==, i know you can over ride equales, and you can't overrdie ==, but how?

Lets say i have java class Dogs, and if dogs are from same kind i want them to be equale, how can i do it?

    public class Dogs{
        private String dogKind;

        public Dogs(String kind){
            this.dogKind = kind
        }

        public String getDogKind(){
            return this.dogKind;
        }
     }

So where in how i override equales?

Please try to read and search online before asking a very basic question — Gigalala, May 25 '14 at 08:59

Gigalala · Accepted Answer · 2014-05-25T09:16:16.873

0

Just simply read online(So many good answers), and if you dont understand:

You need to add this in the Dogs class, simply do:

    @Override
    public boolean equals(Object obj) {
        if (!obj instanceof Dogs){
            return false;
        }
        return this.dogKind.equals(((Dogs)obj).getDogKind());
    }

The first part makes sure that the object given to the method is not null or from a different class.

The second part simply uses String equals, to check if the Strings are the same or not.

edited May 25 '14 at 09:16

answered May 25 '14 at 08:58

Gigalala

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also you forgot about hashcode – nikis May 25 '14 at 09:00
true, il change it in a sec – Gigalala May 25 '14 at 09:00
who ever, changed it thank you, i was in the middle of changing it myself :-) – Gigalala May 25 '14 at 09:05
The `null` check is redundant - if `obj` is `null` `obj instanceof Dogs` will be `false`. – Idan Arye May 25 '14 at 09:05
Idan Arye, are you sure? – Gigalala May 25 '14 at 09:07

What is the difference between equales and ==

1 Answers1