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Question

How do I check if an object given to me is an int [] in Java?

Answer 1

+22 A:

The way you'd expect:

if (theObject instanceof int[]) {
    // use it!
}

Arrays are Objects, even if they're arrays of primitives.

Michael Myers 2009-04-23 19:18:31

Yep. That's the way to do it. I knew there was a better way than my answer.

MBCook 2009-04-23 19:22:11

Answer 2

A:

Get the runtime class of the variable if its a single dimension array the class name is like [int if it is a 2 dimensional array the class name is [[int and if it's a 3 dimensional class name is [[[int

if ( j.class.Name.equals("[int")) {
   ......
}

S M Kamran 2009-04-23 19:23:58

Reflection would also work, but the question didn't mention multidimensional arrays.

Michael Myers 2009-04-23 19:25:43

That should be j.getClass().getName(), not j.class.Name.

Michael Myers 2009-04-23 19:29:18

j.class would work in Java 6 as well and if it's not then the point is however communicated well. However the instanceof would be better because I think it's deduced at compile time with out a call to a class method. However for the sake of providing a different proposition I'm adding this.

S M Kamran 2009-04-23 19:32:03

I downloaded Java 6 specifically to test this, and it doesn't seem to work. "class" does not seem to be a member accessible from an instance, at least not in JDK1.6.0_13

skiphoppy 2009-04-23 21:15:50

Answer 3

+1 A:

if (o instanceof int[])
{
...
}

Arrays are Objects in java.

Schildmeijer 2009-04-23 19:33:45

Answer 4

A:

intanceof is simplest but to do literally what you ask.

if (o.getClass() == int[].class)

Peter Lawrey 2009-04-23 19:39:42

important to note: instanceof will not throw a NullPointerException if o is null, but this will

Kip 2009-04-23 19:49:39

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How do I check if an object given to me is an int [] in Java?

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