10 Class and Methods

10.1 | Class

A class is a template from which objects are created. A class declaration typically contains a set of attributes (instance variables) and functions (methods).



Class



10.2 | Methods

In Java, functions, and procedures are called methods. Methods can include zero or more input parameters and zero or one return parameter. The following code shows some method declarations. An arithmetic class has two methods printSum and getSum. method printSum has two input parameters both of integer type and no return parameter. while method getSum has two integer type input parameter and one integer type return parameter.





10.2.1 | Method Overloading

In Java, method overloading occurs when two or more methods in the same class have the same name but different parameters. Two methods can be considered overloaded if any of the below conditions are true:
  • The number of parameters is different for the methods.
  • The parameter types (input or return) are different.
Class ArithmeticClass below has two methods with same name getSum. these two methods are overloaded as the number of input parameters is different of both.

Arithmetic Class



10.2.2 | Method Overriding

Overriding a method involves defining a method in a subclass that has the same signature (input and return parameter) as a method in a superclass. Then, when that method is called, the method in the subclass is found and executed instead of the one in the superclass. The following code overriding method print. The code below shows the classes SuperClass and SubClass. SubClass overrides the print method of its superclass. MainClass shows different ways of calling the overridden method of a subclass as well as the original method of the superclass.

Super Class


10.2.3 | Variable and Method Scope

Java has reserved keywords to define the scope of variables methods and classes. 

private keyword is used to declare variables and methods that are to be accessible only within the class. 

protected keyword is used to declare variables and methods that are to be accessible only within the class or any class that extends to this class.

public keyword is used to declare variables and methods that are to be accessible within the class and as well as outside of class.


3 comments:

viswanath said...

AWS Training in Bangalore - Live Online & Classroom
myTectra Amazon Web Services (AWS) certification training helps you to gain real time hands on experience on AWS. myTectra offers AWS training in Bangalore using classroom and AWS Online Training globally. AWS Training at myTectra delivered by the experienced professional who has atleast 4 years of relavent AWS experince and overall 8-15 years of IT experience. myTectra Offers AWS Training since 2013 and retained the positions of Top AWS Training Company in Bangalore and India.


IOT Training in Bangalore - Live Online & Classroom
IOT Training course observes iot as the platform for networking of different devices on the internet and their inter related communication. Reading data through the sensors and processing it with applications sitting in the cloud and thereafter passing the processed data to generate different kind of output is the motive of the complete curricula. Students are made to understand the type of input devices and communications among the devices in a wireless media.

Anonymous said...

Hadoop concepts, Applying modelling through R programming using Machine learning algorithms and illustrate impeccable Data Visualization by leveraging on 'R' capabilities.With companies across industries striving to bring their research and analysis (R&A) departments up to speed, the demand for qualified data scientists is rising.
data science training in bangalore


Python is a high-level, interpreted, interactive and object-oriented scripting language. Python is designed to be highly readable. It uses English keywords frequently where as other languages use punctuation, and it h
as fewer syntactical constructions than other languages.python interview questions and answers

Aruna Ram said...

This post is very kind of details with comprehensive content. Please share with us more unique posts...
Excel Training in Chennai
Advanced Excel Training in Chennai
Unix Training in Chennai
Linux Training in Chennai
Job Openings in Chennai
Placement in Chennai
Social Media Marketing Courses in Chennai
Power BI Training in Chennai
Excel Training in Velachery
Excel Training in T Nagar