Articles : JavaBoutique's Introduction to Java :
Java Classes :

Contents
Classess
Abstract Classes and Interfaces
Methods
Overloading
Inheritance
Examples
Defining a Class
Instantiating and Using an Object

Methods

As we said earlier in our discussion of object-oriented programing, methods are the verbs of objects. Methods, like subroutines in procedural-oriented programming, are the basic unit of funtionality of an object. They are a body of executable code contained within a class which can be used to effect an instantiated object of the class.

Methods consist of the following components:

  • A method name
  • A list of inputs which may be empty
  • A return type which may be "void" if the method returns nothing
  • The code to perform some action

Actually, some methods, such as abstract methods, do not require executable code. Abstract methods are used like interfaces to help define a skeleton of functionality but leave the fleshing out to another.

Consider the following code snippet:

int add(int a, int b)
  {
  return (a+b);
  }

In this case, we have created a method which adds two integers passed to it as arguments and then returns the result. The method is named "add" and might be used in your code with a line such as the following in which mySum is set to "7":

int mySum = add(3, 4)

Note that you can only define methods within the body of a class definition so the above code alone would not work unless you made it part of a class.

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Selena Sol contributes to the JavaBoutique's Introduction to Java. Selena curently works for Barclays Capital in London, one of the leading global investment banks in Europe and has worked as a software developer for the National Center for Human Genome research, Microline Software, Neuron Data, and Electric Eye in Singapore. Selena is perhaps best-known for creating the Public Domain Web Script Archive (Extropia) and writing several books on Web Programming (Perl, CGI, Java).
Email: selena@extropia.com