A Programmer[ap]s Guide to Java Certification

• Declare classes, nested classes, methods , instance variables static variables, and automatic (method local) variables making appropriate use of all permitted modifiers (such as public, final, static, abstract, etc.). State the significance of each of these modifiers both singly and in combination and state the effect of package relationships on declared items qualified by these modifiers.

• Identify legal return types for any method given the declarations of all related methods in this or parent classes.

Relevant Sections

Read Sections 4.2 "Defining Classes" and 4.3 "Defining Methods," and all the sections from 4.5 "Scope Rules" till the end of the chapter. For inner classes, see Chapter 7. For method overriding, see Section 6.2.

Study Notes

Modifiers affect classes, methods, and variables and each modifier has a specific significance. Accessibility modifiers specify where classes and methods can be accessed and used. Knowing which modifiers are applicable in a given context is important.