Java - The General Form of a Class

The General Form of a Class

A class is declared by use of the class keyword. The classes that have been used up to this point are actually very limited examples of its complete form. Classes can (and usually do) get much more complex. A simplified general form of a class definition is shown here:

class classname {

type instance-variable1; type instance-variable2; // ...

type instance-variableN;

type methodname1(parameter-list) {

// body of method }

type methodname2(parameter-list) {

// body of method }

// ...

type methodnameN(parameter-list) { // body of method } }

The data, or variables, defined within a class are called instance variables. The code is contained within methods. Collectively, the methods and variables defined within a class are called members of the class. In most classes, the instance variables are acted upon and accessed by the methods defined for that class. Thus, as a general rule, it is the methods that determine how a class’ data can be used.