objective c - Passing NSInteger variable to NSMutableDictionary or NSMutableArray

Question

Why does this not work:

NSInteger temp = 20;
[userSettingsFromFile setObject:temp forKey:@"aTemp"];

but this does:

[userSettingsFromFile setObject:@"someObject" forKey:@"aTemp"];

How can I use the NSInteger variable?

question from:https://stackoverflow.com/questions/1339394/passing-nsinteger-variable-to-nsmutabledictionary-or-nsmutablearray

Answer 1

NSInteger isn't an object -- it's simply typecast to int on 32-bit or long on 64-bit. Since NSDictionary can only store objects, you need to wrap the integer into an object before you can store it. Try this:

NSInteger temp = 20;
[userSettingsFromFile setObject:[NSNumber numberWithInteger:temp] 
                         forKey:@"aTemp"];