Book Image

Oracle Certified Associate, Java SE 7 Programmer Study Guide

By : Richard M. Reese
Book Image

Oracle Certified Associate, Java SE 7 Programmer Study Guide

By: Richard M. Reese

Overview of this book

<p>Java SE 7 Associate Programmer certification adds to your qualification as a Java developer. Knowledge of Java is important, but knowing how to write an efficient and productive code adds to your skills and gives you an edge when you are planning to give the certification exam. Coverage of the objectives goes beyond a simple review of certification objectives.</p> <p>"Oracle Certified Associate, Java SE 7 Programmer Study Guide" addresses certification exam objectives and provides discussion and examples to show the best ways of applying Java language features in real world programming. You will gain in-depth understanding of Java by examining how objects are allocated in the heap and how methods are managed in the program stack.<br /><br />"Oracle Certified Associate, Java SE 7 Programmer Study Guide" covers all of the Java SE 7 Associate Programmer certification objectives. It starts with a high level overview of an application’s structure to provide a framework for subsequent chapters. Chapters are organized around common themes with emphasis on memory usage. You will get an in-depth and complete understanding of the run-time Java environment using the illustrations that show the impact of class and method usage on the program stack and heap. <br /><br />Augmenting the coverage of certification objectives are examples of how you can use the classes, methods, and techniques in a productive and sound manner. In addition, sample exam questions are given in each chapter.</p>
Table of Contents (16 chapters)
Oracle Certified Associate, Java SE 7 Programmer Study Guide
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface

Arrays


An array allows multiple values to be accessed using a single variable name. Each element of an array is of the same type. The element type can be a simple primitive data type or a reference to an object.

One-dimensional arrays are allocated to a contiguous region of memory. This means that the elements of the array can be accessed efficiently as they are adjacent to each other. Arrays use an integer index to access an element in the array. Indexes range from 0 to the length of the array minus one. We are able to access the elements of an array directly, in any order as needed by the application, without having to visit each element.

Though Java supports multidimensional arrays, one-dimensional arrays are most commonly used. Arrays can be used for a variety of purposes including:

  • A collection of numbers representing ages

  • A list of employee names

  • A list of prices for an item in a store

The main disadvantage of arrays is that they have a fixed size. This makes it more difficult and less...