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According to, http://www.freshvanilla.org:8080/display/www/Java+Interview+Questions
Under
Which class is the superclass of every class?
null seems to be the answer.
I found that
new Object().getClass().getSuperClass()
verifies the answer as correct.
But can null be considered a class?
I see all primitive data types are represented as Class objects from
java.lang.Class's documentation.
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A class is never null - a reference to an instance may be null. The design question is: Who creates the instance? You could make it return an Option<'T> instead of a 'T. Then users cannot ignore the fact that sometimes there is None...
null is not an Object or neither a type. It's just a special value, which can be assigned to any reference type. Typecasting null to any reference type is fine at both compile-time and runtime and it will not throw any error or exception.
3. Type of null: Unlike the common misconception, null is not Object or neither a type.
In Java programming, null can be assigned to any variable of a reference type (that is, a non-primitive type) to indicate that the variable does not refer to any object or array.
Remember that the Class class is itself a class. So when you call c.getClass() you're getting back an instance of the Class class. So because there is no super class of Object, the getSuperClass() method cannot return anything so it returns null.
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