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
Preface

Type Casting


To convert an int of value of 23 into a long literal, we would need to do what is called type casting:

int num_int = 23;
long num_long = (long)num_int;

In the second line, we cast the num_int of the int type to a long literal by using the notation (long)num_int. This is referred to as casting. Casting is the process of converting one data type into another. Although we can cast a long to an int, remember that the number might be outside the int range and some numbers will be truncated if they can't fit into the int.

As is with int, long can also be in octal, hexadecimal, and binary, as shown in the following code:

long num = 117L;
long hex_num = 0x75L;
long oct_num = 0165L;
long bin_num = 0b1110101L;

Exercise 5: Type Casting

It's often important to change one type to another. In this exercise, we will convert an integer into a floating point:

  1. Import Scanner and create a public class:

    import java.util.Scanner;
     
    public class Main
     
    { 
        static Scanner sc = new Scanner(System.in);...