Introduction 1 About This Book 1 Foolish Assumptions 2 Icons Used in This Book 3 Beyond the Book 4 Where to Go from Here 4 Part 1: Getting Started with Java 5 Chapter 1: All about Java 7 What You Can Do with Java 8 Why You Should Use Java 9 Gaining Perspective: Where Java Fits In 10 Object-Oriented Programming (OOP) 12 Object-oriented languages 13 Objects and their classes 15 What''s so great about an object-oriented language? 15 Objects and classes are everywhere 18 What''s Next? 19 Chapter 2: All about Software 21 Get Ready for Java 21 The Inside Scoop 23 What is a compiler? 24 What is a Java virtual machine? 27 Developing Software 31 Spoiler Alert! 32 Chapter 3: Using the Basic Building Blocks 33 Speaking the Java Language 33 The grammar and the common names 34 The words in a Java program 35 Checking Out Java Code for the First Time 37 Understanding a Simple Java Program 38 The Java class 38 The Java method 40 The main method in a program 41 How you finally tell the computer to do something 43 Brace yourself 45 And Now, a Few Comments 49 Adding comments to your code 49 What''s Barry''s excuse? 53 Using comments to experiment with your code 53 Part 2: Writing Your Own Java Programs 55 Chapter 4: Making the Most of Variables and Their Values 57 Varying a Variable 58 Assignment statements 60 The types of values that variables may have 61 How to hold the line 64 Numbers without decimal points 65 Combining declarations and initializing variables 67 Experimenting with JShell 69 What Happened to All the Cool Visual Effects? 72 The Atoms: Java''s Primitive Types 73 The char type 73 The boolean type 76 The Molecules and Compounds: Reference Types 78 An Import Declaration 82 Creating New Values by Applying Operators 84 Initialize once, assign often 87 The increment and decrement operators 89 Assignment operators 93 Chapter 5: Controlling Program Flow with Decision-Making Statements 97 Making Decisions (Java if Statements) 98 Guess the number 98 She controlled keystrokes from the keyboard 99 Creating randomness 102 The if statement 103 Equal, equal 104 Brace yourself 105 Your intent to indent 105 Elseless in Helsinki 106 Using Blocks in JShell 108 Forming Conditions with Comparisons and Logical Operators 109 Comparing numbers; comparing characters 109 Comparing objects 110 Look! 113 Java''s logical operators 115 Vive les nuls! 118 (Conditions in parentheses) 119 The Nesting Habits of if Statements 121 Choosing among Many Alternatives 124 Java''s glorious switch statement 124 A switch in time saves 14 127 Your grandparents'' switch statement 130 Free fall 131 Chapter 6: Controlling Program Flow with Loops 135 Repeating Instructions Over and Over Again (Java while Statements) 136 Count On Me 139 The anatomy of a for statement 141 The world premiere of "Al''s All Wet" 142 You Can Always Get What You Want 145 The root of the matter 148 Reading a single character 149 File handling in Java 150 Block on the while side 151 Part 3: Working with the Big Picture: Object-Oriented Programming 155 Chapter 7: The Inside scOOP 157 Defining a Class (What It Means to Be an Account) 158 Declaring variables and creating objects 163 Initializing a variable 166 Using an object''s fields 167 One program; several classes 167 Declaring a public class 167 Defining a Method within a Class (Displaying an Account) 169 An account that displays itself 170 The display method''s header 172 Sending Values to and from Methods (Calculating Interest) 173 Passing a value to a method 176 Returning a value from the getInterest method 178 Giving Your Numbers a Makeover 180 Hide-and-Seek 185 Good programming 185 Public lives and private dreams: Making a field inaccessible 188 Enforcing rules with accessor methods 190 Barry''s Own GUI Class 190 Chapter 8: Saving Time and Money: Reusing Existing Code 199 What It Means to Be an Employee 200 The last word on employees 200 Putting your class to good use 202 Cutting a check 206 Working with Disk Files (a Brief Detour) 207 Storing data in a file 207 Repeat after me 208 Reading from a file 209 Who moved my file? 212 You moved your file! 212 Reading a line at a time 213 Clean up after yourself 215 Defining Subclasses (What It Means to Be a Full-Time or Part-Time Employee) 216 Creating a subclass 218 Creating subclasses is habit-forming 220 Using Subclasses 221 Making types match 223 The second half of the story 224 Changing the Payments for Only Some of the Employees 225 A Java annotation 227 Using methods from classes and subclasses 228 Chapter 9: Constructing New Objects 233 Defining Constructors (What It Means to Be a Temperature) 234 What is a temperature? 235 What is a temperature scale? (Java''s enum type) 235 Okay, so then what is a temperature? 236 What you can do with a temperature 238 Constructing a temperature; a slow-motion replay 240 Some things never change 243 Doing Something about the Weather 246 Building better temperatures 246 Constructors for subclasses 248 Using all this stuff 249 The default constructor 250 A Constructor That Does More 254 Classes and methods from the Java API 256 Live dangerously 257 Part 4: Smart Java Techniques 259 Chapter 10: Putting Variables and Methods Where They Belong 261 Defining a Class (What It Means to Be a Baseball Player) 262 Another way to beautify your numbers 263 Using the Player class 264 One class; nine objects 266 Don''t get all GUI on me 266 Some facts about potatoes 268 Making Static (Finding the Team Average) 270 Why is there so much static? 272 Meet the static initializer 272 Displaying the overall team average 273 The static keyword is yesterday''s news 276 Could cause static; handle with care 276 Experiments with Variables 279 Putting a variable in its place 280 Telling a variable where to go 283 Passing Parameters 287 Pass by value 288 Returning a result 290 Pass by reference 290 Returning an object from a method 292 Epilogue 294 Chapter 11: Using Arrays to Juggle Values 295 Getting Your Ducks All in a Row 295 Creating an array in two easy steps 298 How to book hotel guests 299 Tab stops and other special things 301 Make life easy for yourself 302 Stepping through an array with the enhanced for loop 304 Do you have a room? 306 Writing to a file 308 When to close a file 309 Arrays of Objects 311 Using the Room class 313 Yet another way to beautify your numbers 316 The conditional operator 317 How to Argue with Your Code 318 Settling the argument 319 Checking for the right number of program arguments 321 Chapter 12: Using Collections and Streams (When Arrays Aren''t Good Enough) 323 Arrays Have Limitations 324 Collection Classes to the Rescue 325 Using an ArrayList 325 Using generics 328 Wrap it up 331 Are we done yet? 333 Once and again 333 So many collection classes! 335 Functional Programming 336 Problem-solving the old-fashioned way 337 Lambda expressions 339 A black sheep among the lambdas 341 A taxonomy of lambda expressions 342 The interpretation of streams 342 Why bother? 348 Method references 351 Chapter 13: Looking Good When Things Take Unexpected Turns 355 Garbage In 356 The parameter in a catch clause 360 Do it yourself 362 Who will catch the exception? 364 Catching two or more exceptions at a time 371 The Buck Stops Here, Except When It Doesn''t 372 Catch it soon 374 Catch it later 375 Checked or unchecked? 377 Try, Try Again! 380 Chapter 14: Sharing Names among the Parts of a Java Program 385 Access Modifiers 386 Classes and Their Members 386 Public and Private Access for Members 387 Drawing on a frame 390 Putting a package in its place 392 Making a frame 394 Default Access for Members 396 Switching to Default access 398 Accessing default members within a package 400 Protected Access for Members 402 A class in one package and a subclass in another 402 Two classes in the same package 404 Access Modifiers for Java Classes 408 Public classes 408 Nonpublic classes 409 From Classes Come Modules 410 Chapter 15: Fancy Reference Types 411 Java''s Types 411 The Java Interface 412 Declaring two interfaces 413 Implementing interface.