Java Tutorial - Compare Objects - Equality Operator Vs Equals Method

Compare Objects - Equality Operator Vs Equals Method.

Hi Everyone and Welcome,

I am continuing on with my video series on Java programming for beginners. In this video, I explain and illustrate using examples a common problem encountered by almost all beginner programmers - the difference between the equality operator '==' and the equals method 'equals()' when comparing Java objects.

I hope you enjoy this video. Any and all comments or feedback is welcome. Thank you.

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[someone]

Helpful video .. Thank you
It would be great if some examples included (so we can see the difference in the output)

[KevinBFG]

This haunted me for a while, I feel a weight off my shoulders! Thank you Martin!!!

[selbywebb]

Best explanation I've seen. And trust me, I've watched a few videos. Your work is appreciated!

[katy]

Awesome teaching!!! Im totally new in Java field and I love all your videos hope continue to educate us. Please make videos for "Generics and Collections" ...Thank you very very much it helps a lot :)

[ca]

Thank you Martin you did GREAT professional explanation

[AndrewOnTestingCars]

Good Man Martin, Great Video ! very well described & clear

[makeupyonkis]

Awesome explanation! Thank you very much! n.n

[callmeMsMori]

Awesome Explanation, but should have shown the output.

[seal]

thx i was going through asserts for Junit and had a hard time understanding the difference between assertEquals and assertSame. From this video seems like assertSame is using == and assertEquals is using .equals(). If the class doesn't have it's own equal method it will act the same way as assertSame or the class it extends that does have a equals method.

[jimcherian]

Hey Martin, Nice video, appreciate it. I have a question, What if I have 100 fields in my class, will i have to write the code to compare all the fields in the overridden equals method

[mayankpatel]

Respected Sir, good explanation. I am new in CSC field. I have written a program in which I have to compare two object's variables. Instance variables are private. 1 object is derived by set and get methods and other object information is derived by prompting the user to get variables for other object to be compared. How to compare in this one with equal method.
Yours Sincerely.

[PapaSmurff]

great video, explained very well! thanks!

[Lanceegan]

Great video Martin. Shouldn't you always override the hascode() method as well?

[Crisikos]

great video, very clear, thanks a lot !!

[ivanpantic]

Great tutorials. Too bad you have only 19.

[hansbrinkhof]

Not impressed, because of a few very basic, yet major issues with your example:
1. The code you show as example will never compile: is missing a closing )
2. A wee bit more important: in your equals method, you compare the values of String (Objects) by using a referential (==) comparison. Your entire point is to teach people not to compare Objects like this.
3. Most important of all: do not, seriously, not, overload the equals method. You should override it. It should always keep the signature:

public boolean equals(Object o) {...}

don't let it take an instance of your class. If you do, you 'll be in trouble once you start working with sorting of collections and such.