CODEWITHSUNDEEP
objective-cdictionarynsdictionary
user2924482
user2924482

Reputation: 9140

iOS: populated NSDictionary valueForKey is returning nil

I have the following NSDictionary:

NSDictionary *myDict = [[NSDictionary alloc] initWithObjectsAndKeys:@"value1", @"key1", @"value2", @"key2", nil];

But when I try to query the dictionary using valueForKey I always get nil value. For example:

po [myDict valueForKey:@"value1"]
 nil

If query the dictionary using objectForKey everything is Ok..

po [myDict objectForKey:@"key1"]
value1

Any of you knows why I'm getting nil when I query the dictionary using valueForKey ?

I'll really appreciate your help.

Upvotes: 0

Views: 118

Answers (1)

rmaddy
rmaddy

Reputation: 318944

valueForKey: should only be used when you have a clear and understood need to use key-value coding. You still need to pass in a key but you are passing in a value. Since there is no key in the dictionary of value1, it correctly returns nil.

But again, don't use valueForKey: unless you have a proper reason.

objectForKey: on key1 works because you actually have a key of key1 in the dictionary.

If you were to call objectForKey:@"value1" it would also return nil.

Upvotes: 1

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