What type of object is this under XCode 4.5: @[rabbit, chicken, owl]

What is the method for adding KVO to your app?

To have an IOS app Screen Design we used which of the following tool?

What does the "id" type mean?

How do you concatenate two NSStrings *foo and NSString *bar to form a new NSString *baz?

Which of the following is a Singleton?

What is different about this function? +(void)doSomething;

What best describes class inheritance in Objective-C?

What does ARC stand for?

What's wrong with this code?float x = 5.;

What is foo? -(float)foo;