What can't be stored in NSDictionary?

Question

I have an online quiz I am trying to complete and this is the question:

One of the following can't be stored in NSDictionary. It can't be stored because it is a _____ type:

UIView NSNumber NSInteger UIColor

Fill in in the blank.

I can't seem to find the answer anywhere online. As far as I can tell they all have a way of being stored in NSDictionary, any ideas?

You're completing a quiz that tests the combined knowledge of the Internet? — Caleb, Nov 12 '14 at 21:02
And here I thought you were wanting to understand the difference between the types... ;-) — Mark McCorkle, Nov 12 '14 at 21:06
This question is part of the "Code With Target" web challenge. — russes, Apr 26 '15 at 23:00
Also structs cannot be stored in NSDictionary, for example CLLocationCoordinate2D — Adam Mendoza, Nov 15 '16 at 08:20

score 5 · Accepted Answer · answered Nov 12 '14 at 21:00

5

NSInteger! because it's a primitive type

answered Nov 12 '14 at 21:00

Puran

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score 2 · Answer 2 · edited May 23 '17 at 12:24

Primitive types since they are not objects. Anything that is an object can be added.

The main difference is related to where they stay in the memory, objects are stored in the heap while value type are stored directly in the Stack ...

heap : is an area of memory used for dynamic memory allocation.

stack : is the section of memory that is allocated for automatic variables within functions. Data is stored in stack using the Last In First Out (LIFO) method.

About NSInteger and NSNumber :

NSInteger is nothing more than a synonym for a long integer, while NSNumber is an Objective-C class, a subclass of NSValue to be specific.

What is the difference between primitive data type vs an non primitive data type(apple defined data type)?

https://developer.apple.com/library/mac/documentation/Cocoa/Reference/Foundation/Classes/NSDictionary_Class/

What can't be stored in NSDictionary?

2 Answers2