Book Image

Java Fundamentals

By : Gazihan Alankus, Rogério Theodoro de Brito, Basheer Ahamed Fazal, Vinicius Isola, Miles Obare
Book Image

Java Fundamentals

By: Gazihan Alankus, Rogério Theodoro de Brito, Basheer Ahamed Fazal, Vinicius Isola, Miles Obare

Overview of this book

Since its inception, Java has stormed the programming world. Its features and functionalities provide developers with the tools needed to write robust cross-platform applications. Java Fundamentals introduces you to these tools and functionalities that will enable you to create Java programs. The book begins with an introduction to the language, its philosophy, and evolution over time, until the latest release. You'll learn how the javac/java tools work and what Java packages are - the way a Java program is usually organized. Once you are comfortable with this, you'll be introduced to advanced concepts of the language, such as control flow keywords. You'll explore object-oriented programming and the part it plays in making Java what it is. In the concluding chapters, you'll get to grips with classes, typecasting, and interfaces, and understand the use of data structures, arrays, strings, handling exceptions, and creating generics. By the end of this book, you will have learned to write programs, automate tasks, and follow advanced courses on algorithms and data structures or explore more advanced Java courses.
Table of Contents (12 chapters)
Java Fundamentals

Constructor Overloading

Just like methods, constructors can be overloaded too. When the same constructors are declared with different parameters in the same class, this is known as constructor overloading. The compiler differentiates which constructor is to be called, depending on the number of parameters and their data types.

In our discussion on constructors, we created a second constructor for our Person class that takes age, height, and weight as parameters. We can have this constructor in the same class as the constructor that takes in no parameters. This is because the two constructors have a different signature and can hence be used side by side. Let's look at how we can do this:

public Person(){
   this(28, 10, 60);
//Overloaded constructor
public Person(int myAge, int myHeight, int myWeight){
   this.age = myAge;
   this.height = myHeight;
   this.weight = myWeight;

The two constructors have same name (the class name) but take different parameters.

Add a third constructor...