When to use NSMutuableArray?

In my app, I plan to have around 3000 CKRecords which I will retrieve and place all of them in an array. I will later have to loop through that array several times. Is this a good time to use NSMutuableArray?

Sure, but CKRecords are key-value pairs which are themselves mutable. So I would think you could still get away with NSArray if you want to move CKRecords. The array doesnt have to be mutable, just the records themselves.

Yes .

When the data is varying then we must use Mutable array or else if it is not changing just use an array . a Simple logic to remember .