NSUserDefault exists -iPHONE SDK

How would I check in a "if" statement if the NSUserDefault object i开发者_如何学Cs saved there or not? I'm not really sure how to call it.. So a pretty short question..

Thanks

if ([[NSUserDefaults standardUserDefaults] objectForKey:@"Foo"] != nil) {
  NSLog(@"an object is saved under \"Foo\"!");
}

Dave's answer is correct, but I'd skip the explicit test for nil:

if ([[NSUserDefaults standardUserDefaults] objectForKey:@"Foo"]) {
    NSLog(@"An object is saved under \"Foo\"!");
}