How to initialize an empty mutable array in Objective C

I have a list of objects (trucks) with various attributes that populate a tableview. When you tap them they go to an individual truck page. There is an add button which will add them to the favorite list in another tableview. How do I initialize an empty mutable array in Cocoa?

I have the following code:

-(IBAction)addTruckToFavorites:(id)sender:(FavoritesViewController *)controller
{
[controller.listOfTrucks addObject: ((Truck_Tracker_AppAppDelegate *)[UIApplication sharedApplication].delegate).selectedTruck];

}


listOfTrucks

8 Answers
8

Update:

With new syntax you can use:

NSMutableArray *myArray = [NSMutableArray new];


Original answer:

for example:

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


And here you find out why (difference between class and instance method)

initWithCapacity:

[NSMutableArray array]

_listOfTrucks

Basically, there are three options:

First

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


Second

NSMutableArray *myMutableArray = [NSMutableArray new];


Third

NSMutableArray *myMutableArray = [NSMutableArray array];


NSMutableArray *arr = [NSMutableArray array];


You can also initialize in this way

Another way for Objective C apart from the answer of @NSSam

NSMutableArray *myMutableArray = [@ mutableCopy];


For Swift

let myArray = NSMutableArray()


OR

let myArray = .mutableCopy() as! NSMutableArray;


listOfTrucks = [NSMutableArray array]; gives you a new mutable array.

listOfTrucks = [NSMutableArray array];

NSMutableArray *arr = [NSMutableArray new];


I use this way to initialize an empty mutable array in Objective C:

NSMutableArray * array = [NSMutableArray arrayWithCapacity:0];


In modern Objective - C it could be even more shorter:

NSArray *array = @


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