OCA Java SE 7 Programmer I Certification Guide: Prepare for the 1ZO-803 exam

Front cover......Page 1
brief contents......Page 8
contents......Page 10
foreword......Page 18
preface......Page 20
acknowledgments......Page 22
Start your preparation with the chapter-based exam objective map......Page 24
Exam tips......Page 25
Images......Page 26
Twist in the Tale exercises......Page 29
Author Online......Page 30
about the author......Page 31
about the cover illustration......Page 32
Introduction......Page 34
2.1 The importance of OCA Java SE 7 Programmer certification......Page 35
2.2 Comparing OCA Java exam versions......Page 36
2.4 Complete exam objectives, mapped to book chapters, and readiness checklist......Page 37
3.1 FAQs on exam preparation......Page 41
3.2 FAQs on taking the exam......Page 43
4 The testing engine used in the exam......Page 45
1 Java basics......Page 46
1.1 The structure of a Java class and source code file......Page 47
1.1.1 Structure of a Java class......Page 48
1.1.2 Structure and components of a Java source code file......Page 54
1.2.1 Executable Java classes versus nonexecutable Java classes......Page 58
1.2.2 Main method......Page 59
1.3.1 The need for packages......Page 62
1.3.2 Defining classes in a package using the package statement......Page 63
1.3.3 Using simple names with import statements......Page 65
1.3.4 Using packaged classes without using the import statement......Page 67
1.3.6 Can you recursively import subpackages?......Page 68
1.3.8 Static imports......Page 69
1.4.1 Access modifiers......Page 70
1.4.2 Public access modifier......Page 72
1.4.3 Protected access modifier......Page 73
1.4.4 Default access (package access)......Page 75
1.4.5 Private access modifier......Page 78
1.5 Nonaccess modifiers......Page 80
1.5.1 Abstract modifier......Page 81
1.5.2 Final modifier......Page 82
1.5.3 Static modifier......Page 84
1.6 Summary......Page 87
1.7 Review notes......Page 88
1.8 Sample exam questions......Page 91
1.9 Answers to sample exam questions......Page 95
2 Working with Java data types......Page 102
2.1 Primitive variables......Page 103
2.1.1 Category: Boolean......Page 105
2.1.2 Category: Numeric......Page 106
2.1.3 Category: Character......Page 111
2.1.4 Confusion with the names of the primitive data types......Page 112
2.2 Identifiers......Page 113
2.2.1 Valid and invalid identifiers......Page 114
2.3.1 What are object reference variables?......Page 115
2.3.2 Differentiating between object reference variables and primitive variables......Page 117
2.4 Operators......Page 118
2.4.1 Assignment operators......Page 120
2.4.2 Arithmetic operators......Page 122
2.4.3 Relational operators......Page 125
2.4.4 Logical operators......Page 127
2.4.5 Operator precedence......Page 129
2.6 Review notes......Page 131
2.7 Sample exam questions......Page 134
2.8 Answers to sample exam questions......Page 137
3 Methods and encapsulation......Page 143
3.1.1 Local variables......Page 145
3.1.2 Method parameters......Page 147
3.1.3 Instance variables......Page 148
3.1.4 Class variables......Page 149
3.1.5 Overlapping variable scopes......Page 150
3.2.1 An object is born......Page 153
3.2.2 Object is accessible......Page 155
3.2.3 Object is inaccessible......Page 156
3.3 Create methods with arguments and return values......Page 157
3.3.1 Return type of a method......Page 158
3.3.2 Method parameters......Page 160
3.3.3 Return statement......Page 163
3.4 Create an overloaded method......Page 165
3.4.1 Argument list......Page 166
3.4.3 Access modifier......Page 168
3.5 Constructors of a class......Page 169
3.5.1 User-defined constructors......Page 170
3.5.2 Default constructor......Page 173
3.5.3 Overloaded constructors......Page 175
3.6.2 Read and write object fields......Page 178
3.6.3 Calling methods on objects......Page 181
3.7.1 Need for encapsulation......Page 183
3.7.2 Apply encapsulation......Page 184
3.8.1 Passing primitives to methods......Page 186
3.8.2 Passing object references to methods......Page 188
3.10 Review notes......Page 191
3.11 Sample exam questions......Page 195
3.12 Answers to sample exam questions......Page 199
4 String, StringBuilder, Arrays, and ArrayList......Page 207
4.1 Welcome to the world of the String class......Page 208
4.1.1 Creating String objects......Page 209
4.1.2 The class String is immutable......Page 212
4.1.3 Methods of the class String......Page 215
4.1.4 String objects and operators......Page 219
4.1.5 Determining equality of Strings......Page 220
4.2 Mutable strings: StringBuilder......Page 222
4.2.2 Creating StringBuilder objects......Page 223
4.2.3 Methods of class StringBuilder......Page 225
4.3.1 What is an array?......Page 230
4.3.2 Array declaration......Page 232
4.3.3 Array allocation......Page 233
4.3.4 Array initialization......Page 234
4.3.5 Combining array declaration, allocation, and initialization......Page 236
4.3.6 Asymmetrical multidimensional arrays......Page 237
4.3.7 Arrays of type interface, abstract class, and class Object......Page 238
4.4 ArrayList......Page 239
4.4.1 Creating an ArrayList......Page 240
4.4.2 Adding elements to an ArrayList......Page 242
4.4.3 Accessing elements of an ArrayList......Page 244
4.4.4 Modifying the elements of an ArrayList......Page 245
4.4.5 Deleting the elements of an ArrayList......Page 246
4.4.6 Other methods of ArrayList......Page 248
4.5.2 Comparing objects of a user-defined class......Page 254
4.5.3 Incorrect method signature of the equals method......Page 256
4.5.4 Contract of the equals method......Page 257
4.6 Summary......Page 258
4.7 Review notes......Page 260
4.8 Sample exam questions......Page 265
4.9 Answers to sample exam questions......Page 269
5 Flow control......Page 276
5.1.1 The if construct and its flavors......Page 278
5.1.2 Missing else blocks......Page 281
5.1.3 Implications of the presence and absence of {} in if-else constructs......Page 282
5.1.4 Appropriate versus inappropriate expressions passed as arguments to an if statement......Page 284
5.1.5 Nested if constructs......Page 285
5.2.2 Comparing a switch statement with multiple if-else constructs......Page 287
5.2.3 Arguments passed to a switch statement......Page 290
5.2.4 Values passed to the label case of a switch statement......Page 291
5.2.5 Use of break statements within a switch statement......Page 292
5.3 The for loop......Page 293
5.3.1 Initialization block......Page 295
5.3.3 The update clause......Page 296
5.3.4 Nested for loop......Page 297
5.4 The enhanced for loop......Page 298
5.4.1 Limitations of the enhanced for loop......Page 301
5.4.2 Nested enhanced for loop......Page 302
5.5 The while and do-while loops......Page 303
5.5.1 The while loop......Page 304
5.5.2 The do-while loop......Page 305
5.6.1 Comparing do-while and while loops......Page 307
5.6.2 Comparing for and enhanced for loops......Page 308
5.7.1 The break statement......Page 309
5.7.2 The continue statement......Page 311
5.7.3 Labeled statements......Page 312
5.9 Review notes......Page 313
5.10 Sample exam questions......Page 316
5.11 Answers to sample exam questions......Page 320
6 Working with inheritance......Page 328
6.1.1 Need to inherit classes......Page 329
6.1.2 A derived class contains within it an object of its base class......Page 333
6.1.5 Derived classes can define additional properties and behaviors......Page 334
6.1.6 Abstract base class versus concrete base class......Page 335
6.2 Use interfaces......Page 337
6.2.1 Properties of members of an interface......Page 340
6.2.3 Implementing multiple interfaces......Page 341
6.3 Reference variable and object types......Page 343
6.3.1 Using a variable of the derived class to access its own object......Page 344
6.3.3 Using a variable of an implemented interface to access a derived class object......Page 345
6.3.4 The need for accessing an object using the variables of its base class or implemented interfaces......Page 346
6.4.1 How to cast a variable to another type......Page 349
6.4.2 Need for casting......Page 351
6.5.1 Object reference: this......Page 352
6.5.2 Object reference: super......Page 354
6.6.1 Polymorphism with classes......Page 357
6.6.2 Binding of variables and methods at compile time and runtime......Page 362
6.6.3 Polymorphism with interfaces......Page 363
6.7 Summary......Page 366
6.8 Review notes......Page 367
6.9 Sample exam questions......Page 369
6.10 Answers to sample exam questions......Page 373
7 Exception handling......Page 381
7.1.1 A taste of exceptions......Page 382
7.1.2 Why handle exceptions separately?......Page 385
7.1.3 Do exceptions offer any other benefits?......Page 386
7.2 What happens when an exception is thrown?......Page 387
7.2.1 Creating try-catch-finally blocks......Page 389
7.2.2 Will a finally block execute even if the catch block defines a return statement?......Page 394
7.2.3 What happens if both a catch and a finally block define return statements?......Page 395
7.2.4 What happens if a finally block modifies the value returned from a catch block?......Page 396
7.2.5 Does the order of the exceptions caught in the catch blocks matter?......Page 397
7.2.6 Can I rethrow an exception or the error I catch?......Page 399
7.2.8 I can create nested loops, so can I create nested try-catch blocks too?......Page 400
7.3.1 Identifying exception categories......Page 402
7.3.2 Checked exceptions......Page 403
7.3.3 Runtime exceptions (also known as unchecked exceptions)......Page 404
7.3.4 Errors......Page 405
7.4 Common exception classes and categories......Page 407
7.4.1 ArrayIndexOutOfBoundsException and IndexOutOfBoundsException......Page 408
7.4.2 ClassCastException......Page 409
7.4.4 IllegalStateException......Page 411
7.4.5 NullPointerException......Page 412
7.4.6 NumberFormatException......Page 415
7.4.7 ExceptionInInitializerError......Page 417
7.4.9 NoClassDefFoundError......Page 419
7.5 Summary......Page 420
7.6 Review notes......Page 421
7.7 Sample exam questions......Page 426
7.8 Answers to sample exam questions......Page 430
8.1 Mock exam......Page 438
8.2 Answers to mock exam questions......Page 472
A.1.1 Twist in the Tale 1.1......Page 535
A.1.3 Twist in the Tale 1.3......Page 536
A.2.1 Twist in the Tale 2.1 (part 1)......Page 537
A.2.3 Twist in the Tale 2.2......Page 538
A.2.5 Twist in the Tale 2.4......Page 539
A.3.2 Twist in the Tale 3.2......Page 541
A.4.1 Twist in the Tale 4.1......Page 542
A.4.3 Twist in the Tale 4.3......Page 543
A.5.1 Twist in the Tale 5.1......Page 544
A.5.2 Twist in the Tale 5.2......Page 545
A.5.4 Twist in the Tale 5.4......Page 546
A.6.2 Twist in the Tale 6.2......Page 547
A.6.4 Twist in the Tale 6.4......Page 548
A.7.2 Twist in the Tale 7.2......Page 549
A.7.5 Twist in the Tale 7.5......Page 550
A......Page 552
C......Page 553
E......Page 554
F......Page 555
I......Page 556
M......Page 557
O......Page 558
S......Page 559
T......Page 560
W......Page 561
Back cover......Page 562