how can you find out if an NSObject has a certain property?

objective-c properties weak-linking
strawtarget picture strawtarget · Jun 17, 2010 · Viewed 10.4k times · Source

Let's say in Apple API version 1.0, there is a class NSFoo with a property 'color'. API 1.1 adds property 'size'.

I want to know whether I can use the getter: myFoo.size

[myFoo respondsToSelector:@selector(getSize)] doesn't work as expected.

What's the correct way to find out if an object has a property? Thanks!

Answer

mbauman picture mbauman · Jun 17, 2010

You're close. Your selector should be exactly the message you want to send to the object:

if ( [myFoo respondsToSelector:@selector(size)] ) {
    int size = [myFoo size]; // or myFoo.size in dot-notation.
    // ...
}

should work.

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