Creating variables in Java

Creating variables in Java means that we have to declare a variable. If we also want to use it, we have to initialize it. As you most likely know, declaration is the process of assigning a type and a name. Initializing is about giving the variable an actual value:

int number = 3;

char letter = 'z';

Here, we declare the variable and initialize it on the same line. We declare it with the type and name. The types here are int and char and the variable names are number and letter. This can also be separated over multiple lines as follows:

double percentage;

percentage = 8.6;

The JVM doesn’t check the types anymore – this is done by the compiler prior to running the application. There is actually a difference between the storage of primitive types and reference types. This is what we’re going to look at now.

Primitives and reference types

The JVM deals with two types of variables: primitives and reference...