Android Java class casting

Question

I am wondering if someone could explain something about a class cast for me.

I am playing around with Android and I have a subclass of Application named ExApp.

I want to call a method of ExApp from one of my activities, so I do:

ExApp ex = ((ExApp)getapplication());

What I don't understand is why I need a double set of parentheses? Why can't I just:

ExApp ex = (ExApp)getApplication();

?

Thanks.

Jon Skeet · Accepted Answer · 2011-05-29 07:31:33Z

8

You can. The two statements are exactly the same.

Where you'd see a difference is if you were calling a method on the result, e.g.

(ExApp) getApplication().foo();

is different to:

((ExApp) getApplication()).foo();

In the first case, it's the result of foo() which is cast to ExApp; in the second, it's the result of ExApp, and the overall expression is the return type of foo().

answered May 29, 2011 at 7:31

Jon Skeet

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