About modifying contents of NSMutableArray

Question

I have a NSMutableArray , called buttonContainer that contains UIButton s. The thing is I want to change the CGRectmake() of every button with a new value, is there an easy way to do this?

I'm trying this but get errors:

[buttonContainer objectAtIndex: i].frame = CGRectmake(x,y,w,h);

The error I get is: property 'frame' not found on object of type 'id'.

Answer 1

A NSMutableArray can contain any id type, and the return type of objectAtIndex is id which does not has a frame property. If your array contains only UIButton then you can do this inside loop:

UIButton *button = (UIButton *) [buttonContainer objectAtIndex:i];
button.frame = CGRectMake(x, y, w, h);

Answer 2

What you really want to do is use IBOutletCollection .

You declare them in your @interface files and add your buttons to this collection, and then you can run a method over each object in the collection.

You can see more details here