How do I store an NSRange in a NSMutableArray or other container?

Question

Here's what I want to do:

NSRange r = NSMakeRange(0,5);
id a = [NSMutableArray a];
[a addObject: r]; // but NSRange is not a NSObject *

With a boolean, I'd use code like this:

[a addObject: [NSNumber numberWithBool: YES]];

or with an integer:

[a addObject: [NSNumber numberWithInteger: 3]];

So what's the equivalent with a NSRange? What I don't really want to do is create my own subclass of NSObject to accomplish this. Surely there's a way with what Apple's already provided?

Emelineemelita

Answer 1

Use NSValue's +valueWithRange:. To retrieve the range structure back, use the property rangeValue.

[a addObject:[NSValue valueWithRange:r]];
...

NSRange r = a[4].rangeValue;

Dinnerware

Why NSValue could store NSRange but NSArray could not? – Roundly

Because NSArray can store objects only. NSRange is not an object, but you can wrap it with NSValue so it can be used by NSArray, NSDictionary etc. – Gastrulation

while iterating through NSMutable array , NSRange r = a[i].rangeValue giving error like property range value not found on type id... – Mariel

@jayantrawat: The type of the array a should be generic: NSMutableArray<NSValue*>*. – Dinnerware

Answer 2

[NSValue valueWithRange:r];

and get it back out with:

NSRange r = [rangeObject rangeValue];

Monopolize

what is rangeobject? – Mariel

Answer 3

If you need to store the NSRange in a property list, you can also turn an NSRange into an NSString using the NSStringFromRange function. And then, you can turn that string back into a range using the NSRangeFromString function.

Alex

Upvoting because this is clever and useful, but NSValue seems less elbowy. Thanks. :) – Emelineemelita

Thanks! I just learned about NSValue myself from the other answers (thanks @Monopolize and @KennyTM), and it's definitely less elbowy than my suggestion. To be more deserving of your kind upvote, I updated my answer to mention that the string version can be useful with storing ranges in property lists. – Alex

Answer 4

One other option might be to add those ranges into an NSIndexSet, depending on how you intend to use them next.

Gobbledygook