Variables are an important feature of Java, which makes it a true object oriented language. In Java, there are many categories of variables in use such as local and instance variables. Java classes have different methods that manipulate various attributes of particular objects of interest. When writing a program, programmers usually declare attributes of class outside a method, but inside a class declaration. However, there are cases where objects within a class keep their own copy of attributes for variables. The fields used to refer to these variables are known as instance variable because each object within a class keeps their own instance of the variable in memory during runtime (Deitel & Deitel, 2011).