Java Method - Tutorial 1

A method is just a chunk of code that does a particular job. But methods are set out in a certain way. You have a method header, and a method body. The header is where you tell Java what value type, if any, the method will return (an int value, a double value, a string value, etc). As well as the return type, you need a name for your method, which also goes in the header. You can pass values over to your methods, and these go between a pair of round brackets. The method body is where you code goes.


A simple Java method requires a minimum of three items:

Visibility : public, private, protected
Return Type: void, int, double, (etc.)
name: whatever you want to call the method

Visibility means who can access it. If it is public, anyone who has access to your class file can access the method. In some circumstances, this is perfectly fine. If the method is private, only the functions inside of that class can call the method. This is used as utility methods to do something you do not want just anyone who uses the class to do. Protected gives public function to all child classes.

Return type is void if you do not want the method to give you any data back. It would be used for such things as a method that prints out something. Any other return requires a return statement with the type of data it returns. For example, if you add two integers and want the results of that integer, your return type would be int.

Name of the method is anything you choose that is not already used in the class (unless you are overloading the method which is beyond the scope of this article)

If you want the method to do something with the data you supply it, you also need to include parameters within the ( ) You include what data type it is and give that parameter a name (ie: you are declaring a local variable for that method only) 

How to invoke (call) a method (method invocation):

When a method is invoked (called), a request is made to perform some action, such as setting a value, printing statements, returning an answer, etc.  The code to invoke the method contains the name of the method to be executed and any needed data that the receiving method requires.  The required data for a method are specified in the method's parameter list. 

example :

int temp = thisIsMethod("Koko", 17); 

or

System.out.println(thisIsMethod("Koko", 17));