Can't check if int is null

Question

I'm trying to use a dictionary. Whenever I want to check if an element is present in the dictionary, I do this:

int value = results.get("aKeyThatMayOrMayNotBePresent");

if (value != null)
  // ...

But then the compiler says I can't compare an int to a <nulltype>. What's the correct way to check for null in this case?

Answer 1

You're comparing a primitive value (int) to null. Since primitives cannot be null, you should use a corresponding object, such as Integer in this case. So, you should write

Integer value = results.get("aKeyThatMayOrMayNotBePresent");