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Java Fundamentals

You're reading from   Java Fundamentals A fast-paced and pragmatic introduction to one of the world's most popular programming languages

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Product type Paperback
Published in Mar 2019
Publisher
ISBN-13 9781789801736
Length 408 pages
Edition 1st Edition
Languages
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Authors (5):
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Miles Obare Miles Obare
Author Profile Icon Miles Obare
Miles Obare
Basheer Ahamed Fazal Basheer Ahamed Fazal
Author Profile Icon Basheer Ahamed Fazal
Basheer Ahamed Fazal
Rogério Theodoro de Brito Rogério Theodoro de Brito
Author Profile Icon Rogério Theodoro de Brito
Rogério Theodoro de Brito
Gazihan Alankus Gazihan Alankus
Author Profile Icon Gazihan Alankus
Gazihan Alankus
Vinicius Isola Vinicius Isola
Author Profile Icon Vinicius Isola
Vinicius Isola
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Table of Contents (12) Chapters Close

Java Fundamentals
Preface
1. Introduction to Java 2. Variables, Data Types, and Operators FREE CHAPTER 3. Control Flow 4. Object-Oriented Programming 5. OOP in Depth 6. Data Structures, Arrays, and Strings 7. The Java Collections Framework and Generics 8. Advanced Data Structures in Java 9. Exception Handling Appendix

Constructors


To be able to create an object of a class, we need a constructor. A constructor is called when you want to create an object of a class. When we create a class without a constructor, Java creates an empty default constructor for us that takes no parameters. If a class is created without a constructor, we can still instantiate it with the default constructor. A good example of this is the Person class that we used previously. When we wanted a new object of the Person class, we wrote the following:

Person me = new Person();

The default constructor is Person(), and it returns a new instance of the Person class. We then assign this returned instance to our variable, me.

A constructor is just like any other method, except for a few differences:

  • A constructor has the same name as the class

  • A constructor can be public or private

  • A constructor doesn't return anything, even void

Let's look at an example. Let's create a simple constructor for our Person class:

public class Person {
   //Properties...
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