iOS: Statically Create an NSArray Object in View Controller

When you have an NSArray object containing NSString objects in your View Controller, you might want to create a static version of it, especially when the user will only see the same values each time the view appears.

First, add your C array pointers to NSString constants by following instructions in my earlier post.
In Constants.h:

extern NSString * const kMenuItems[];

In Constants.m:

NSString * const kMenuItems[] = {
    @"ABC", @"123", @"Do Re Me"

Make sure you import Constants.h in your view controller class. If you have other constants that span across most of classes, you might want to add Constants.h into a PCH File (see instructions in my previous post).

Next, add a new method in your view controller class:

+ (NSArray *)topicArray {
    static NSArray *topics;
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        topics = [NSArray arrayWithObjects:kMenuItems count:3];
    return topics;

The onceToken will ensure that your NSArray object is created once.

Finally, use it in your class’ viewDidLoad method:

topicArray = [[self class] topicArray];

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