Get all keys of an NSDictionary as an NSArray

Question

Is it possible to get all the keys from a specific NSDictionary as a seperate NSArray?

score 191 · Accepted Answer · answered Aug 14 '11 at 13:30

191

Just use

NSArray*keys=[dict allKeys];

In general, if you wonder if a specific class has a specific method, look up Apple's own documentation. In this case, see NSDictionary class reference. Go through all the methods. You'll discover many useful methods that way.

answered Aug 14 '11 at 13:30

Yuji

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3

To get the first key only is NSString *firstKey = [dict allKeys][0]; – Mazen Kasser Nov 06 '13 at 04:30
2

@MazenKasser `firstObject` is a safer solution - in case if the dictionary doesn't have any keys the app won't crash: `dict.allKeys.firstObject;` – Islam Oct 20 '15 at 05:12
1

the order of keys returned by allKeys is undefined... so allKeys.firstObject or allKeys][0] is dangerous either way – Bradley Thomas Feb 24 '17 at 19:39

score 17 · Answer 2 · answered Aug 14 '11 at 13:30

17

Yes it's possible. Use allKeys method:

NSDictionary *yourDictionary;
NSArray * yourKeys
yourKeys = [yourDictionary allKeys];

answered Aug 14 '11 at 13:30

gsempe

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score 3 · Answer 3 · answered Nov 12 '16 at 18:20

3

And if you want to get all keys and values, here's what you do:

for (NSString *key in dictionary) {
    id value = dictionary[key];
    NSLog(@"Value: %@ for key: %@", value, key);
}

answered Nov 12 '16 at 18:20

awfulcode

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12

Get all keys of an NSDictionary as an NSArray

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