How do I add an object to a dictionary in objective-c

Question

I have a dictionary and want to add a new object to it but compiler give error that it not mutable.

like code below:

dict[@"key"] = @"something new";

Already asked and answered: https://stackoverflow.com/questions/6519957/add-values-in-nsmutabledictionary-in-ios-with-objective-c — fisehara, Sep 27 '17 at 15:05
Show us the exact error message. If the dictionary is defined and init as a `NSDictionary`, why not using `NSMutableDictionary` instead? — Larme, Sep 27 '17 at 15:09
Possible duplicate of [Add values in NSMutableDictionary in iOS with Objective-C](https://stackoverflow.com/questions/6519957/add-values-in-nsmutabledictionary-in-ios-with-objective-c) — Andrey Belykh, Sep 27 '17 at 15:34

score 0 · Accepted Answer · answered Sep 27 '17 at 15:04

0

You are trying to mutate an immutable object. You need to create a mutable copy and the add the new key-value

NSMutableDictionary *mut = [dict mutableCopy];
mut[@"new key"] = @"new value";

answered Sep 27 '17 at 15:04

Avba

score 0 · Answer 2 · answered Mar 30 '18 at 02:22

0

If you want to keep the dictionary immutable, you can do:

NSDictionary* dict = [NSDictionary dictionaryWithObjectsAndKeys:@"something new", @"key", nil];

answered Mar 30 '18 at 02:22

Jigar Gada

2 Answers2