Difference between NSArray and NSMutableArray

Question

What is the difference b/w NSArray and NSMutableArray?

Answer 1

NSMutableArray (and all other classes with Mutable in the name) can be modified. So, if you create a plain NSArray, you cannot change its contents later (without recreating it). But if you create an NSMutableArray, you can change it — you'll notice it has methods like -addObject: and -insertObject:atIndex:.

See the documentation for details.