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

The this Keyword

In our Person class, we saw the following line in our constructor:

age = myAge;

In this line, as we saw earlier, we are setting the age variable in our current object to the new value, myAge, which is passed in as a parameter. Sometimes, we wish to be explicit about the object we are referring to. When we want to refer to the properties in the current object we are dealing with, we use the this keyword. As an example, we could rewrite the preceding line as follows:

this.age = myAge;

In this new line, this.age is used to refer to the age property in the current object we are dealing with. this is used to access the current object's instance variables.

For example, in the preceding line, we are setting the current object's age to the value that's passed into the constructor.

In addition to referring to the current object, this can also be used to invoke a class' other constructors if you have more than one constructor.

In our Person class, we will create a second constructor that...