Questions and answers

How do I add an object to NSArray?

How do I add an object to NSArray?

NSArray is immutable. Use the mutable version, NSMutableArray. NSMutableArray * customTickLocations = [NSMutableArray new]; for (int idx = 0; idx < 12; ++idx) { [customTickLocations addObject:[NSDecimalNumber numberWithInt:idx]]; } you cannot add Objects at run time to NSArray.

How to add object in NSArray in objective c?

Objective-C Language NSArray Add objects to NSArray NSArray *a = @[@1]; a = [a arrayByAddingObject:@2]; a = [a arrayByAddingObjectsFromArray:@[@3, @4, @5]];

What is an add object?

Adding Objects Adds the objects contained in another given array to the end of the receiving array’s content. Inserts a given object into the array’s contents at a given index. – insertObjects:atIndexes: Inserts the objects in the provided array into the receiving array at the specified indexes.

What is difference between NSArray and NSMutableArray?

The primary difference between NSArray and NSMutableArray is that a mutable array can be changed/modified after it has been allocated and initialized, whereas an immutable array, NSArray , cannot. This syntax creates an instance of an array for us.

What is NSArray?

NSArray is Objective-C’s general-purpose array type. It represents an ordered collection of objects. NSArray is immutable, so we cannot dynamically add or remove items. Its mutable counterpart, NSMutableArray, will be discussed in the second part of this tutorial.

How do I know if my NSArray is empty?

NSArray has the count method, a common way to do it would be… That will check if the array has nothing in it, or if it is set to nil. While we are all throwing out the same answers, I thought I would too. if([myarray count]) It checks for both not empty and nil array.

How do you make an empty NSArray?

in C I can simply declare an array like this: int array[500]; to declare an array of size 500 which can then be filled later.

Is Swift empty?

To check if string is empty in Swift, use the String property String. isEmpty . isEmpty property is a boolean value that is True if there are no any character in the String, or False if there is at least one character in the String.

What is a NSArray?

How to create an NSArray object in Objective-C?

In addition to the provided initializers, such as initWithObjects:, you can create an NSArray object using an array literal. In Objective-C, the compiler generates code that makes an underlying call to the init (objects:count:) method.

What is nsmutablearray and what does NSArray do?

NSArray and its subclass NSMutableArray manage ordered collections of objects called arrays. NSArray creates static arrays, and NSMutableArray creates dynamic arrays. You can use arrays when you need an ordered collection of objects. NSArray is “toll-free bridged” with its Core Foundation counterpart, CFArray.

Is there a way to subclass the NSArray class?

In addition to the provided instance methods, such as object (at:), you can access NSArray values by their indexes using subscripting. There is typically little reason to subclass NSArray. The class does well what it is designed to do—maintain an ordered collection of objects.

How to check if an element exists in the NSArray?

Note: To check if a given element exists in the NSArray, containsObject: method is used with the string literal passed as the parameter. To retrieve the index of an NSArray element, indexOfObject: method is used. This either returns the index of the first occurrence of the requested object or NSNotFound if it’s not in the array.