Duplicate code adds unnecessary bulk to the class. Java provides a way to avoid this duplication by offering this() syntax for having one constructor call another: class Book { // ... Book(String ...

Classes and objects in Java must be initialized before they are used. You’ve previously learned that class fields are initialized to default values when classes are loaded, and that objects are ...

String s1 = new String("Hello world!"); That code will create an s1 string object and a reference variable. As noted, Java strings are immutable. Once created, a string using string class cannot be ...

A popular academic exercise is to create a program that determines if a number or String is a palindrome ... see if you can implement your own Java palindrome program with loops, arrays and maybe even ...