Question

I have an object that got parsed into an NSString and when I trace out the class name, it says NCDecimalNumber. Why? (I understand NSString is a cluster, but still don’t understand why NSDecimalNumber would be a part of what’s behind the cluster)

The following post asks a similar question but no one answers the why.
Converting NSDecimalNumber to NSString

Answer 1

This sounds like the decoder decodes the number into an NSDecimalNumber (and strings into NSStrings).

Remember, Objective-C is C, so you can effectively assign anything to a pointer, it is up to you to ensure that the types correspond. This is why you can assign an object of type NSNumber to a pointer declared to be of type NSString*. As you can see, class clusters don’t have anything to do with this.

So before assigning your object to a variable, you should check the class or, alternatively, just assign the object to a pointer of type id (which can hold any object).

If you need to work on the objects based on their type, you can do something like this:

id obj = //...

if ( [obj isKindOfClass: [NSString class]] ) {

}
else if ( [obj isKindOfClass: [NSNumber class]] ) {

}
else {

}