Review

Encapsulation:

• Fundamental concept of object-oriented programming
• Wraps the data (variables) and code that acts on the data (methods) in one unit (class)
• Why make instance variables private?
• Restrict access (read-only)
• Option to provide validation checks
• make instance variables private for CSA
• Getters: return value of variable/data
• Setters: Set value of variable/data

//Single line comment// /* multi linecomment */

Accessor methods (“Getters”)

• Allow safe access to instance variables -often referred to get methods/getters
• Must be public (provide visibility to everything esle) -Return type must match the type of the instance variable to be accessed
• No parameters -Naming conventions getNameOfVariable toString method
• Overridden method that is included in classes to provide a diescription of a specific object (includes what values are stored in the the instance data of the object

Mutator methods (“setters”)

• Mutator methods are often void methods that change the values of instance variables or static variables

When static is used in a method, the class owns the method When you don’t use static, an individual object owns the method

Static methods

• Associated with class, not object
• Include keyword static in the header
• Static methods cannot access instance variables
• Do not have a this reference, unable to use class instance variables or call non static methods

Variable scope

• Local variables can be declared in the body of constructors and methods - may only be used within the constructor or method - cannot be declared public or private
• When there is a local variable with the same name as an instance variable, it will refer to the local
• Formal parameters and variables declared in a method or constructor can only be used within that method or constructor