Objective-C LanguageNSMutableArray

Adding elements

NSMutableArray *myColors;
myColors = [NSMutableArray arrayWithObjects: @"Red", @"Green", @"Blue", @"Yellow", nil];
[myColors addObject: @"Indigo"];
[myColors addObject: @"Violet"];

//Add objects from an NSArray
NSArray *myArray = @[@"Purple",@"Orange"];
[myColors addObjectsFromArray:myArray];

Insert Elements

NSMutableArray *myColors;
int i;
int count;
myColors = [NSMutableArray arrayWithObjects: @"Red", @"Green", @"Blue", @"Yellow", nil];
[myColors insertObject: @"Indigo" atIndex: 1];
[myColors insertObject: @"Violet" atIndex: 3];

Deleting Elements

Remove at specific index:

[myColors removeObjectAtIndex: 3];

Remove the first instance of a specific object:

[myColors removeObject: @"Red"];

Remove all instances of a specific object:

[myColors removeObjectIdenticalTo: @"Red"];

Remove all objects:

[myColors removeAllObjects];

Remove last object:

[myColors removeLastObject];

Sorting Arrays

NSMutableArray *myColors = [NSMutableArray arrayWithObjects: @"red", @"green", @"blue", @"yellow", nil];
NSArray *sortedArray;
sortedArray = [myColors sortedArrayUsingSelector:@selector(localizedCaseInsensitiveCompare:)];

Move object to another index

Move Blue to the beginning of the array:

NSMutableArray *myColors = [NSMutableArray arrayWithObjects: @"Red", @"Green", @"Blue", @"Yellow", nil];

NSUInteger fromIndex = 2;
NSUInteger toIndex = 0;

id blue = [[[self.array objectAtIndex:fromIndex] retain] autorelease];
[self.array removeObjectAtIndex:fromIndex];
[self.array insertObject:blue atIndex:toIndex];

myColors is now [@"Blue", @"Red", @"Green", @"Yellow"].

Filtering Array content with Predicate

Using filterUsingPredicate: This Evaluates a given predicate against the arrays content and return objects that match.


      NSMutableArray *array = [NSMutableArray array];
      [array setArray:@[@"iOS",@"macOS",@"tvOS"]];
      NSPredicate *predicate = [NSPredicate predicateWithFormat:@"SELF beginswith[c] 'i'"];
      NSArray *resultArray = [array filteredArrayUsingPredicate:predicate];

Creating an NSMutableArray

NSMutableArray can be initialized as an empty array like this:

NSMutableArray *array = [[NSMutableArray alloc] init];
// or
NSMutableArray *array2 = @[].mutableCopy;
// or
NSMutableArray *array3 = [NSMutableArray array];

NSMutableArray can be initialized with another array like this:

NSMutableArray *array4 = [[NSMutableArray alloc] initWithArray:anotherArray];
// or
NSMutableArray *array5 = anotherArray.mutableCopy;