Why does an object of type Integer turn to a primitive type?

Question

So I have this code:

public static void main( String[] args )
{
    int i = 3;
    int j = new Integer(5);

    JOptionPane.showMessageDialog(null, Boolean.toString(j.equals(5)));
}

It should open a message dialog with the text "true". The problem is it gives a compiler error saying that I can't invoke a method on the primitive type int. Why is this happening?

Casting ((Integer) j).equals(5) works as expected. I just don't understand why the object j is turning into a primitive type.

Because you are explicitly stating that `j` should be used as an `int` and not as an `integer`? — TheLostMind, Feb 19 '18 at 10:17
because you *declared* `j` to be an `int`, not an `Integer`. — luk2302, Feb 19 '18 at 10:17

score 3 · Answer 1 · answered Feb 19 '18 at 10:18

3

I just don't understand why the object j is turning into a primitive type.

Because j is not an object in the first place. It is a primitive int. Your new Integer(5) is automatically unboxed on assignment.

answered Feb 19 '18 at 10:18

lexicore

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Why does an object of type Integer turn to a primitive type?

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