NSDictionary中的NSNumber始终为null

Question

I'm building a project and want to add a NSNumber into a NSDictionary. But the it crashed because of the null value. So, I created another small program to check what happened. As you can see in the snapshot: Why the the value of NSNumber in NSDictionary is null?

Answer 1

I've run your code and I could reproduce the problem. But it seems like a debugger problem. For instance, if after your dictionary is created, go to the console and try printing the dictionary.

po dictionary

My result is like:

$4 = 0x2083e770 {
    number = 1;
}

So it's not null at all. Also, after that, anum is assigned correctly and b is set to YES. So it really looks like a debugger issue instead of a bug from you.