Index

E

element access expression, 207

else clause

adding to if statements, 24

else keyword, 794

email messages, 331

Enabled property

Button class, 709

encapsulation, 78, 142

changing private features, 145

collections, 205

ensuring data integrity, 143

preventing unauthorized access to data, 142

using accessors within methods, 148

EndsWith method

String class, 450

Enroll method

Section class, 573, 741

enum keyword, 794

enumeration objects

stepping through collections, 489

equality testing (==), 25

Equals method

Object class, 467

errors

null reference exception, 605

escape characters, 448

event delegates, 723

event handling, 673

writing methods, 726

event keyword, 794

EventArgs class

writing event handler methods, 726

events

changing states of objects, 387

displaying information on GUIs, 390

internal, 391

objects

collaboration, 91

directing events to another object, 388

ignoring, 390

returning values, 389

scenarios, 391

types of, 387

Exception class

extending, 462

hierarchy, 458

Message property, 462

System namespace, 458

writing event handler methods, 726

exception handling, 452

catch blocks

proper ordering of, 459

sequential evaluation of, 458

complier-mandated, 465

Exception class

hierarchy, 458

mechanics of, 453

nesting try statements, 460

referencing thrown exception objects, 461

try—catch blocks, 453

user-defined exceptions, 462

exception traces, 607

exclusive or, 373

explicit casting, 22

explicit keyword, 794

expressions, 16

arithmetic statements, 17

assignment statements, 17

compound assignment operators, 17

evaluating and operator precedence, 20

extending abstract classes

compared to implementing interfaces, 261

extending base classes, 181

extending collection classes, 222

Extensible Markup Language. See XML

extern keyword, 794