Understanding type compatibility is fundamental to writing good Java programs ... t compatible to any other type, nor can a primitive and a reference type ever be compatible.

The default constructor in Java takes no arguments -- it simply initializes reference types to null and primitive types to the binary equivalent of zero. That means instance variables are assigned as ...

Many programming languages allow passing objects by reference or by value. In Java, we can only ... what will happen to the primitive types in the following code example? public class ...

It means that on newer JDKs, a wrapper class will be created automatically when a primitive type is used anywhere a reference type is expected ... exists to validate them, as this Java autoboxing ...