Data types

Java is a strongly typed language

It is very important to state at the outset in which Java is a strongly typed language indeed, category of Java's safety and robustness comes from this fact.

1.   Each variable has a type, each expression has a type, and each type is strictly defined.

2.   Second, all assignments, whether explicit or through parameter passing in method calls, are checked for type compatibility. There is no automatic coercion or conversions of conflicting category as in a few languages.

The Java compiler checks all expressions and parameters to ensure in which the types are compatible. A few type mismatches are errors that must be forested before the compiler will finish compiling the class.