Index

( ) parentheses, 2.8
; semicolon, 1.3, 2.9
= assignment operator, 2.2
== equals operator, 5.1, 11.7
[ ] square brackets, 7.1
% remainder operator, 3.8
{} curly braces, 1.3, 5.2
<> angle brackets, 13.9
ArithmeticException, 2.10, D.2
ArrayIndexOutOfBoundsException, 7.2, D.2
ArrayList, 13.9, 14.1
Arrays class, 7.3, 7.4
AWT, 10.1, C, C.4
abecedarian, 6.13
abstract class, 16.3, 16.5
accessor, 11.4
accumulator, 7.5, 7.10
addition
- integer, 2.5
- string, 2.8
- time, 11.8
address, 3.1, 3.11, 11.6
algorithm, 1.8, 1.10
alias, 7.4, 7.10
aliasing, 10.5, 13.5
allocate, 7.1, 7.10
anagram, 7.11
and operator, 5.5
angle brackets, 13.9
args, 9.5
argument, 4.3, 4.7, 4.10
array, 7.1, 7.10
- 2D, 12.11
- copying, 7.4
- element, 7.2
- index, 7.2
- length, 7.4
- of cards, 13
- of objects, 12.6
- of strings, 12.2
- printing, 7.3
assignment, 2.2, 2.11, 5.1
attribute, 10.1, 10.12
automatic conversion, 2.6, 3.7, 4.3, 5.1
BigInteger, 9.7
Boole, George, 5.1
base case, 8.2, 8.9
binary, 8.6, 8.9
binary search, 12.8, 12.10
block, 5.2, 5.11
boolean, 5, 5.8, 5.11
bottom-up design, 14.5, 14.7
bounding box, C.2, C.4
brackets
- angle, 13.9
- square, 7.1
branch, 5.2, 5.11
breakpoint, A.6, A.8
bug, 1.8, 1.10
byte code, 1.4, 1.10
Canvas, C.1
Card, 12.1
CardCollection, 14.1
Character, 9.4, 9.6
Checkstyle, A.5
CodingBat, 8.8
Color, C.2
Convert.java, 3.9, B.4
CPU, 1.1
Crazy Eights, 14
call stack, 8.2, A.6, A.8
camel case, 4.1
case-sensitive, 1.3, 2.1, 4.1, 6.10
catch, 15.8
chaining, 5.3, 5.11
char, 1.5, 6.5
charAt, 6.5
class, 1.3, 1.10, 11.9
- definition, 11
- relationships, 14.6
- utility, 3.2
- wrapper, 9.4
class diagram, 10.7, 10.12, 13.8, 14.6
class variable, 12.3, 12.10
client, 11.4, 11.9
collection, 13.9, 13.11
command-line interface, 9.5, A.3, A.8, B.4
comment, 1.10, 5.10
- documentation, B, B.2
- end-of-line, 1.3, B
- multiline, B
compareTo, 6.10, 12.4
comparison operator, 5.1
compile, 1.4, 1.10, D.1
compile-time error, 2.9, 2.11, D
complete ordering, 12.4
composition, 4.7, 4.10, 14.6
computer science, 1.8, 1.10
concatenate, 2.8, 2.11, 9.11
concrete class, 16.4, 16.5
conditional statement, 5.2, 5.11
constant, 3.4, 3.11
constructor, 11.2, 11.9, 12.1, 13.1, 13.5
- value, 11.3
coordinate, 10.1, C.2, C.4
countdown, 8.1
counter, 7.7
De Morgan’s laws, 5.6, 5.11
Deck, 13.1
Double, 9.4
Doubloon.java, 7.9
DrJava, A.1
debugger, A.6, A.8
debugging, 1.8, 1.10, D
- by bisection, D.1
- experimental, 1.9
- rubber duck, D.3
declaration, 2.1, 2.11, 10.1
decrement, 6.2, 6.12
degrees, 4.6
dependent, 11.4
description, B.3, B.5
design process, 4.9, 9.8, 9.10, 13.2, 14.5, 16.2
deterministic, 7.6, 7.10
diagram
- class, 10.7, 13.8, 14.6
- memory, 2.3, 6.8, 7.4, 9.1, 10.1, 11.2, 11.7, 12.2, 13.1
- stack, 4.5, 8.2, 8.3, 8.7
divisible, 3.8
division
- floating-point, 2.6
- integer, 2.5, 2.6
documentation, 3.9, 10.6, B.1, B.5
- Javadoc comments, B.2
- Javadoc tags, B.3
dot notation, 10.1, 10.12
double, 2.6
doubloon, 6.13
Echo.java, 3.2
Eights, 14.5
efficiency, 7.7, 9.11, 12.7, 13.4, 13.12, 14.1, 17.9
element, 7.1, 7.2, 7.10
empty array, 9.5, 9.10
empty string, 6.7, 6.12
encapsulate, 9.8, 9.10
encapsulation, 9.11, 10.4
- and generalization, 9.8
encode, 12.1, 12.10
enhanced for loop, 7.8, 7.10
equals, 6.10, 11.7, 11.7
equivalent, 11.7, 11.9, 12.4
error
- compile-time, 2.9, D
- logic, 2.10, D, D.3
- message, 1.9, 2.9, 2.9, D.1
- rounding, 2.7
- run-time, 2.10, D
- syntax, D.1
escape sequence, 1.7, 1.10, 6.5
exception, 2.10, D, D.2
- Arithmetic, 2.10
- ArrayIndexOutOfBounds, 7.2
- InputMismatch, 5.9
- Interrupted, 15.7
- MissingFormatArgument, 3.6
- NegativeArraySize, 7.1
- NullPointer, 9.2, 9.6, 12.6
- NumberFormat, 9.4
- StackOverflow, 8.2
- StringIndexOutOfBounds, 6.7, 9.6
executable, 1.4, 1.10
experimental debugging, 1.9
expression, 2.5, 2.11, 4.7, 4.7, 5.7
- big and hairy, D.3
extends, 14.2, 14.2
extract digits, 3.8
FileNotFoundException, D.2
factorial, 8.3, 8.9, 9.11
fibonacci, 8.4
final, 3.4, 12.3, 12.5
flag, 5.7, 5.11
floating-point, 2.6, 2.11
flow of execution, 4.2, 4.10, D.2
for, 6.3
- enhanced, 7.8
format specifier, 3.5, 3.11, 6.4
format string, 3.5, 3.11, 11.5
frame, 4.5, 4.10
GitHub, ??
Goodbye.java, 1.5
Google style, 1.6
Graphics, 15.4, C.1
Greenfield, Larry, 1.9
GuessStarter.java, 3.12
garbage collection, 10.9, 10.12, 12.3
generalization, 9.11, 10.4, 17, 17.10
generalize, 9.8, 9.10
getter, 11.4, 11.9
HAS-A, 14.6, 14.7, 15.4, 16.4
Hand, 14.2
Hello.java, 1.3
HTML, 10.6, B, B.3
hacker, 5.9, 5.11, 9.6
hanging, D.2
hardware, 1.1, 1.10
helper method, 13.2, 13.11
hexadecimal, 3.1, 3.5, 11.6
high-level language, 1.4, 1.10
histogram, 7.7, 7.10, 12.11
IDE, A, A.8
ImageIO, 17.8
InputMismatchException, 5.9
Integer, 9.4
InterruptedException, 15.7
IS-A, 14.6, 14.7, 15.4, 16.4, 17.5
identical, 11.7, 11.9
if statement, 5.2
immutable, 9.3, 9.10, 10.10, 12.5
import statement, 3.2, 3.11
increment, 6.2, 6.12
incremental development, 4.9, 4.10
independent, 11.4
index, 6.12, 7.2, 7.10, 12.6
indexOf, 6.8
infinite loop, 6.1, 6.12, D.2
infinite recursion, 11.2, D.2
information hiding, 11.1, 11.9
inheritance, 14.2, 14.6, 14.7, 17, 17.7
initialize, 2.2, 2.11, 5.7
inner loop, 6.4
instance, 11, 11.9
instance method, 11.6, 11.8, 11.9
instance variable, 11.1, 11.9
instantiate, 11, 11.9
integer division, 2.5, 2.6
interactions, A.2
interface, 17.7
interpret, 1.4, 1.10
invoke, 4.1, 4.10
iteration, 6.3, 6.7, 6.12
iterative, 8, 8.9
JAR, A.1, A.8
Java Tutor, 4.5, 8.8
Javadoc, 10.6, A.1, B, B.3, B.5
JDK, A.1, A.8, B
JFrame, 15.6, C.1
JVM, 1.4, A.1, A.8
java.awt, 10.1, C
java.io, 3.1
java.lang, 3.2
java.math, 9.7
java.util, 3.2
javac, 1.4, 9.5, A.3
javax.imageio, 17.8
keyword, 2.1, 2.11, 11.2
Linux, 1.9
Logarithm.java, 5.10
language
- elements, 3.3
- high-level, 1.4
- low-level, 1.4
leap of faith, 8.4, 8.9, 13.7
length
- array, 7.4
- string, 6.7
library, 3.1, 3.11, 10.6
literal, 3.4, 3.11
local variable, 4.3, 4.10
logic error, 2.10, 2.11, D, D.3
logical operator, 5.5, 5.11, 12.4
long, 4.6
loop, 6.1, 6.12
- for, 6.3
- infinite, 6.1
- nested, 6.4, 12.6
- search, 12.7
- while, 6.1

loop body, 6.1, 6.12
loop variable, 6.4, 6.12, 7.2
low-level language, 1.4, 1.10
Math, 4.6
Mickey Mouse, C.3
MissingFormatArgumentException, 3.6
magic number, 3.4, 3.11
main, 1.3, 4.1
map to, 12.1
memory, 1.1, 1.10
memory diagram, 2.3, 2.11, 6.8, 7.4, 9.1, 10.1, 11.2, 11.7, 12.2, 13.1
mental model, 4.5, D.3
merge, 13.6
merge sort, 13.4, 13.11
method, 1.3, 1.10
- abstract, 16.3
- accessor, 11.4
- boolean, 5.8
- constructor, 11.2
- equals, 11.7, 11.7
- getter, 11.4
- helper, 13.2
- instance, 11.6, 11.8
- modifier, 14.1
- mutator, 11.4
- parameters, 4.4
- setter, 11.4
- static, 11.8
- toString, 11.6
- value, 4.8
modifier method, 14.1
modulo, 3.8, 3.11
modulus, 3.8, 3.11
multidimensional array, 15.3, 15.11
mutable, 10.4, 10.10, 10.12
mutator, 11.4
NaN, 5.11
NegativeArraySizeException, 7.1
NewLine.java, 4.1
NullPointerException, 9.2, 9.6, D.2
NumberFormatException, 9.4
neighbor, 15.1, 15.9
nested, D.2
- arrays, 15.4
- conditions, 5.3
- loops, 6.4
nesting, 5.3, 5.11, 12.6
new, 3.2, 3.12, 7.1, 10.1, 11.2
newline, 1.5, 1.10, 8.1
next
- Scanner, 5.9
nextInt
- Random, 7.6
- Scanner, 3.4
nondeterministic, 7.6, 7.10
not operator, 5.5
null, 9.2, 12.6
Object class, 14.2
object, 9, 9.10
- array of, 12.6
- as parameter, 10.2
- displaying, 11.6
- mutable, 10.4
- type, 11
object code, 1.4, 1.10
object-oriented, 9, 9.10, 10.4, 14.6, 16.4
off-by-one, 13.5, 13.11
operand, 2.5, 2.11
operator, 2.5, 2.11
- assignment, 5.1
- cast, 3.7
- logical, 5.5, 12.4
- new, 3.2, 3.12, 7.1, 10.1, 11.2
- redirection, A.4
- relational, 5.1
- remainder, 3.8
- string, 2.8
or operator, 5.5
order of operations, 2.8, 2.11, D.3
ordering, 12.4
outer loop, 6.4
overload, 11.3, 13.5
overloaded, 6.9, 6.12
override, 11.6, 11.9, 14.8
Pile, 13.9
Player, 14.4
Point, 10.1
PrintTime.java, 4.4
PrintTwice.java, 4.3
package, 3.1, 3.11
paint, C.1
palindrome, 8.10
param tag, B.3
parameter, 4.3, 4.10, 10.2
- multiple, 4.4
parameter passing, 4.3, 4.10
parentheses, 2.8
parse, 2.9, 2.11, 9.4, 9.10
partial ordering, 12.4
pi, 4.6
pixel, C.2, C.4
polymorphism, 17.5, 17.7, 17.10
portable, 1.4, 1.10
precedence, 2.8, D.3
primitive, 9.1, 9.10
print, 1.5, 11.6
print statement, 1.3, 1.10, 11.5, D.2, D.3
printArray, 7.3
printDeck, 12.6, 13.1
printf, 3.5, 6.11, 11.5
println, 1.3
printPoint, 10.2
printTime, 11.5
private, 10.7, 11.1, 11.4
problem solving, 1, 1.10
processor, 1.1, 1.10
program, 1.2, 1.10
programming, 1.2, 1.10
prompt, 3.4, 3.11
protected, 16.3
pseudocode, 13.2, 13.11
pseudorandom, 7.6, 7.10
public, 4.1
quote mark, 1.5, 6.5, D.1
RAM, 1.1
Random, 7.6
Rectangle, 10.3
RGB, C.2, C.4
radians, 4.6
randomInt, 13.2
rank, 12
rational number, 11.10
recursion, 8.3
- infinite, 11.2, D.2
recursive, 8, 8.9
redirection operator, A.4, A.8
reduce, 7.5, 7.7, 7.10
refactor, 16.2, 16.5
reference, 7.2, 7.10, 10.1, 10.5, 12.2, 13.5
relational operator, 5.1, 5.11
remainder, 3.8
replace, 9.3
repository, ??
return, 4.8, 5.10, 10.3
- inside loop, 12.7
return statement, D.3
return tag, B.3
return type, 4.8, 4.10
return value, 4.8, 4.10
rounding error, 2.7, 2.11
row-major order, 15.3, 15.11
rubber duck, D.3
run-time error, 2.10, 2.11, 5.9, 12.6, D
Scanner, 3.2
Scrabble, 6.13, 11.10
StackOverflowError, 8.2, 11.2, D.2, D.2
String class, 10
StringBuilder, 10.11, 13.12
StringIndexOutOfBoundsException, 6.7, 9.6
Surprise.java, 10.10
System.err, 5.9, A.7
System.in, 3.2, 9, A.4
System.out, 3.1, 3.1, 9, A.4
scaffolding, 4.9, 4.10
scope, 4.5, 4.10, 10.8
search, 7.5, 7.10
selection sort, 13.3, 13.11
semicolon, 1.3, 2.9
sequential search, 12.7, 12.10
setter, 11.4, 11.9
shadowing, 11.3, 11.9
short circuit, 5.5, 5.11, 9.6
shuffle, 13.2, 13.2
signature, B.1, B.5
sleep, 15.7
sort
- merge, 13.4
- selection, 13.3
source code, 1.4, 1.10, 10.6
specialization, 17, 17.10
sprite, 17.8, 17.10
src.zip, 10.6
stable configuration, 15.1
stack diagram, 4.5, 4.10, 8.2, 8.3, 8.7
stack trace, 3.6, 3.11, D.2
state, 2.3, 2.11, 3.10, 8.2, 14.4, 15.2, 16.1
statement, 1.3, 1.10
- assignment, 2.2
- catch, 15.8
- conditional, 5.2
- declaration, 2.1, 10.1
- else, 5.2
- for, 6.3
- if, 5.2
- import, 3.2
- initialization, 5.7
- print, 1.5, 11.6, D.2, D.3
- return, 4.8, 5.10, 10.3, 12.7, D.3
- switch, 5.4
- throw, 17.4
- try, 15.8
- while, 6.1
static, 11.2, 11.8, 12.3
static context, 13.8, 13.11
string, 1.5, 1.10
- array of, 12.2
- comparing, 6.10, 9.1
- format, 6.11, 11.6
- length, 6.7
- operator, 2.8
- reference to, 12.2
stub, 4.9, 4.10
style guide, 1.6
subclass, 14.2, 14.7
subdeck, 13.5
substring, 6.9
suit, 12
superclass, 14.2, 14.7
swapCards, 13.2
switch statement, 5.4
syntax, D
syntax errors, D.1
Thread.sleep, 15.7
Time, 11.1
- addition, 11.8
Torvalds, Linus, 1.9
table
- two-dimensional, 9.8
tag, B.3, B.5
temporary variable, 4.8, 4.10, D.3
terminal, A.3
testing, 4.9, 5.9, 13.12, A.4
text editor, A.1, A.8
this, 10.8, 11.2, 13.8, 14.1
throw, 17.4
toCharArray, 7.9
token, 3.3, 3.11
toLowerCase, 9.3
top-down design, 13.2, 13.11, 14.5
toString, 10.2, 11.6
toUpperCase, 9.3
tracing, 4.5, 12.9, A.6, D.2
traversal, 7.5, 7.10, 12.7, 15.4
try, 15.8
type, 2.11
- array, 7.1
- boolean, 5, 5.7
- char, 2.1, 6.5
- double, 2.6
- int, 2.1
- long, 2.7, 4.6
- object, 11
- String, 1.5, 2.1, 10
- void, 4.1
type cast, 3.7, 3.11
UML, 10.7, 10.12, 13.8, 14.6
Unicode, 6.5, 6.12
unit test, A.7, A.8
utility class, 3.2, 7.3
validate, 5.9, 5.11, 9.6
value, 2.1, 2.11
value constructor, 11.3
value method, 4.8
variable, 2.1, 2.11
- instance, 11.1
- local, 4.3
- loop, 6.4, 7.2
- private, 10.7, 11.1, 11.4
- static, 12.3
- temporary, 4.8, D.3
virtual machine, 1.4, 1.10, A.1
void, 4.1, 4.8, 4.10
War (card game), 13.9
while, 6.1
wildcard, A.5, A.8
wrapper class, 9.4, 9.10
wrapper method, 13.11

About the Authors

Allen Downey is a professor of computer science at Olin College of Engineering. He has taught computer science at Wellesley College, Colby College, and UC Berkeley. He has a PhD in computer science from UC Berkeley and master’s and bachelor’s degrees from MIT. Allen is the creator of the best-selling Think series for O’Reilly, which includes Think Python, Think Complexity, Think DSP, and Think Bayes.

Chris Mayfield is an associate professor of computer science at James Madison University, with a research focus on CS education and professional development. He has a PhD in computer science from Purdue University and bachelor’s degrees in CS and German from the University of Utah.

Text © Allen Downey and Chris Mayfield. Interactive HTML © Trinket. Both provided under a CC BY-NC-SA license. Think Java 2nd Edition, Version 7.1.0.