OCA

Introduction xxi Assessment Test xxxi Chapter 1 Java Building Blocks 1 Understanding the Java Class Structure 2 Fields and Methods 2 Comments 4 Classes vs. Files 5 Writing a main() Method 6 Understanding Package Declarations and Imports 9 Wildcards 10 Redundant Imports 11 Naming Conflicts 12 Creating a New Package 13 Code Formatting on the Exam 16 Creating Objects 16 Constructors 17 Reading and Writing Object Fields 18 Instance Initializer Blocks 18 Order of Initialization 19 Distinguishing Between Object References and Primitives 20 Primitive Types 20 Reference Types 24 Key Differences 25 Declaring and Initializing Variables 25 Declaring Multiple Variables 26 Identifiers 27 Understanding Default Initialization of Variables 29 Local Variables 29 Instance and Class Variables 30 Understanding Variable Scope 31 Ordering Elements in a Class 34 Destroying Objects 36 Garbage Collection 36 finalize() 38 Benefits of Java 39 Summary 40 Exam Essentials 41 Review Questions 42 Chapter 2 Operators and Statements 51 Understanding Java Operators 52 Working with Binary Arithmetic Operators 53 Arithmetic Operators 53 Numeric Promotion 55 Working with Unary Operators 57 Logical Complement and Negation Operators 57 Increment and Decrement Operators 58 Using Additional Binary Operators 60 Assignment Operators 60 Compound Assignment Operators 62 Relational Operators 63 Logical Operators 64 Equality Operators 65 Understanding Java Statements 66 The if-then Statement 67 The if-then-else Statement 68 The switch Statement 72 The while Statement 76 The do-while Statement 78 The for Statement 80 Understanding Advanced Flow Control 86 Nested Loops 87 Adding Optional Labels 87 The break Statement 88 The continue Statement 90 Summary 92 Exam Essentials 92 Review Questions 94 Chapter 3 Core Java APIs 101 Creating and Manipulating Strings 102 Concatenation 102 Immutability 104 The String Pool 105 Important String Methods 105 Method Chaining 110 Using the StringBuilder Class 111 Mutability and Chaining 112 Creating a StringBuilder 113 Important StringBuilder Methods 114 StringBuilder vs. StringBuffer 117 Understanding Equality 117 Understanding Java Arrays 119 Creating an Array of Primitives 119 Creating an Array with Reference Variables 121 Using an Array 123 Sorting 124 Searching 125 Varargs 126 Multidimensional Arrays 126 Understanding an ArrayList 129 Creating an ArrayList 129 Using an ArrayList 130 Wrapper Classes 134 Autoboxing 136 Converting Between array and List 136 Sorting 138 Working with Dates and Times 138 Creating Dates and Times 138 Manipulating Dates and Times 142 Working with Periods 145 Formatting Dates and Times 148 Parsing Dates and Times 151 Summary 151 Exam Essentials 152 Review Questions 153 Chapter 4 Methods and Encapsulation 165 Designing Methods 166 Optional Specifiers 168 Return Type 169 Method Name 170 Parameter List 171 Optional Exception List 171 Method Body 171 Working with Varargs 172 Applying Access Modifiers 173 Private Access 173 Default (Package Private) Access 175 Protected Access 176 Public Access 180 Designing Static Methods and Fields 181 Calling a Static Variable or Method 182 Static vs. Instance 183 Static Variables 185 Static Initialization 186 Static Imports 187 Passing Data Among Methods 188 Overloading Methods 191 Creating Constructors 196 Default Constructor 197 Overloading Constructors 199 Final Fields 202 Order of Initialization 202 Encapsulating Data 205 Creating Immutable Classes 207 Writing Simple Lambdas 208 Lambda Example 209 Lambda Syntax 211 Predicates 214 Summary 215 Exam Essentials 216 Review Questions 218 Chapter 5 Class Design 233 Introducing Class Inheritance 234 Extending a Class 235 Applying Class Access Modifiers 237 Creating Java Objects 237 Defining Constructors 238 Calling Inherited Class Members 244 Inheriting Methods 246 Inheriting Variables 257 Creating Abstract Classes 259 Defining an Abstract Class 260 Creating a Concrete Class 262 Extending an Abstract Class 263 Implementing Interfaces 266 Defining an Interface 267 Inheriting an Interface 269 Interface Variables 273 Default Interface Methods 274 Static Interface Methods 278 Understanding Polymorphism 279 Object vs. Reference 281 Casting Objects 282 Virtual Methods 284 Polymorphic Parameters 285 Polymorphism and Method Overriding 287 Summary 288 Exam Essentials 289 Review Questions 291 Chapter 6 Exceptions 299 Understanding Exceptions 300 The Role of Exceptions 300 Understanding Exception Types 302 Throwing an Exception 304 Using a try Statement 305 Adding a finally Block 307 Catching Various Types of Exceptions 309 Throwing a Second Exception 311 Recognizing Common Exception Types 313 Runtime Exceptions 314 Checked Exceptions 317 Errors 317 Calling Methods That Throw Exceptions 318 Subclasses 319 Printing an Exception 321 Summary 323 Exam Essentials 324 Review Questions 325 Appendix A Answers to Review Questions 333 Chapter 1: Java Building Blocks 334 Chapter 2: Operators and Statements 336 Chapter 3: Core Java APIs 339 Chapter 4: Methods and Encapsulation 342 Chapter 5: Class Design 346 Chapter 6: Exceptions 349 Appendix B Study Tips 353 Studying for the Test 354 Creating a Study Plan 354 Creating and Running Sample Applications 355 Taking the Test 359 Understanding the Question 359 Applying Process of Elimination 362 Optimizing Your Time 364 Getting a Good Night's Rest 366 Index 367