What causes "incompatible conditional operand" when using instanceof in Java?

Question

Possible Duplicate:
instanceof - incompatible conditional operand types

I am trying to use below code and getting compilation error.

Class<A> clas; //this is passed from service 
clas instanceof SomeClass

This gives ma the following compilation error:

incompatible conditional operand types Class and SomeClass

Please help me!

Please post some actual code that demonstrates the problem you are having. — Brian Roach, Dec 27 '11 at 06:19
Also look at this link http://stackoverflow.com/questions/3776862/when-should-we-use-instanceof-and-when-not — Dead Programmer, Dec 27 '11 at 06:31

score 7 · Accepted Answer · answered Dec 27 '11 at 06:23

7

instanceof used to check that given object is of type Class(SomeClass - right side parameter). You cannot use Class to check that instanceof another class. To check class equality or assainability you can use SomeClass.isAssignableFrom(clas)

answered Dec 27 '11 at 06:23

Pokuri

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score 1 · Answer 2 · answered Dec 27 '11 at 06:22

From Java Tutorial.

The instanceof operator compares an object to a specified type. You can use it to test if an object is an instance of a class, an instance of a subclass, or an instance of a class that implements a particular interface.

Reference variable clas is not a type of SomeClass or its sub-class.

What causes "incompatible conditional operand" when using instanceof in Java?

2 Answers2