NSMutableDictionary returning null value ? (Objective-C)

Question

After @implementation and before viewDidLoad I declare my NSMutableDictionary as follows :

NSMutableDictionary *dictionary;

Then in my viewDidLoad method I try this :

[dictionary setObject:@"test" forKey:@"haha"];
NSLog(@"%@", [dictionary objectForKey:@"haha"]);

The NSLog returns a null value :

(null)

I would like to know why that happens, it should return "test", doesnt it ?

have you inited your `dictionary` anywhere? like e.g. `dictionary = [NSMutableDictionary new];`...? — holex, Mar 06 '19 at 09:35
This will work. NSMutableDictionary *dictionary = [NSMutableDictionary dictionary]; [dictionary setObject:@"test" forKey:@"haha"]; NSLog(@"%@", [dictionary objectForKey:@"haha"]); — Apparao Mulpuri, Mar 06 '19 at 09:36

score 0 · Accepted Answer · answered Mar 06 '19 at 09:35

0

You will have to instantiate your dictionary first:

[NSMutableDictionary dictionary]

Then it will be ready to use.

answered Mar 06 '19 at 09:35

MCMatan

1

Thanks a lot for your answer, this works fine. I used to work with swift and had to go back to some old Obj-C so I forgot those habits. – julienstack Mar 06 '19 at 10:06

1 Answers1