Access NSMutableArray from another class - Objective C

Question

I have a main ViewController that contains a desginated class. Within that ViewController there is a Container that is linked to an <

Answer 1

What you've done in the code provided is set a public property for a mutable array...

@property (strong, nonatomic) NSMutableArray *selectedCells;

The NSMutableArray is not "created" by setting that property. At some point in your code you also have to create the NSMutableArray by initialising...

NSMutableArray *selectedCells = [[NSMutableArray alloc] init];

or by using a convenience method such as...

NSMutableArray *selectedCells = [NSMutableArray arrayWithCapacity:(NSUInteger)];

or

NSMutableArray *selectedCells = [NSMutableArray arrayWithArray:(NSArray *)];

Initialising an NSMutableArray is often done only once. If it is repeated, the contents are overwritten against the property used to point to the array. As such, a useful location for this is often within the viewDidLoad view controller lifecycle method.