Methods, procedures, functions, subroutines are all basically the same, a chunk of code that does one small task. In Java, each method must be defined in a class.
A method is always followed by a pair of parentheses (). The parentheses may contain parameters or my be left empty if there are no parameters.
Scope of Methods:
- private - can not be used outside of the class it is contained in
- public - can be used by other classes
Return Type
- void -- no data returned
- return data type
Method Parameters
- the list in parenthesis including the data type and local name
- if there are no parameters, the parenthesis are left empty.
Method Signature
Types of methods:
- setters: are used to set the value of an instance field. These types of methods are also known as mutators. A mutator changes (or sets) the value of a variable.
- getters: are used to get the value of an instance field. Used to allow other objects to get the value of a variable.
- constructors: used to create an instance of a object.
- must have the same name as the class it constructs
- the return type is not part of the method header
- behaviors: methods that make the object take action. These allow other objects to ask this object to perform an action. "Tell, don't ask"
Naming a method
- verb or action phrase that describes the action the method will do