Chapter 2

Question 1

Escape sequence for a backspace

Answer 1

\b

Question 2

Escape sequence for tab

Answer 2

\t

Question 3

Escape sequence that creates a new line

Answer 3

\n

Question 4

Escape sequence that is a carriage return

Answer 4

\r

Question 5

Escape sequence for double quotes

Answer 5

"

Question 6

Escape sequence for a single quote

Answer 6

'

Question 7

Escape sequence for a backslash

Answer 7

\

Question 8

Values considered an int

Answer 8

Integers

Question 9

Values considered a double

Answer 9

Decimal values

Question 10

A type of data with only 2 values: true and false.

Answer 10

Boolean

Question 11

What are the three primitive types the AP test requires you to know?

Answer 11

int, double, and boolean

Question 12

A class that is already defined in Java. Objects are assigned using double quotes.

Answer 12

String class

Question 13

Once an object is created their values cannot be changed.

Answer 13

Immutable

Ex. Strings

Question 14

Object and variable name rules

Answer 14

• should begin with a lower case letter
• if 2 words 2nd word capitalized ex. firstName
• or underscore ex. harry_potter
• numbers only after 1st letter ex. r2d2
• no other symbols

Question 15

What index is the 1st letter of a String?

Answer 15

0

Question 16

String Method that returns a number indicating whether this string comes before (negative return value), is equal to (a zero return value), or comes after (positive return value) the string str

Answer 16

int compareTo(String str) 
int val = word.compareTo("Goodbye"); 
//returns 1

Question 17

String Method that returns a new string made up of this string added to (concatenated with) str.

Answer 17

String concat(String str)
Ex. String phrase = word.concat(", how are you");
// returns Hello, how are you

Question 18

String Method that returns the position of the first character in the first occurrence of str in this string.

Answer 18

int indexOf(String str)
Ex. int index = word.indexOf("lo");
//returns 3

Question 19

String Method that returns the number of characters in a string.

Answer 19

int length()
Ex. word.length();
//returns 5

Question 20

String Method that returns a new string that is subset of their string starting at index offset and ending with the character at position endIndex -1

Answer 20

String substring(int offset, int endIndex)
Ex. String shorter = word.substring(1,4);
//returns ell

Question 21

String Method that returns a new string that starts at index offset and extends to the end of the string

Answer 21

String substring(int offset)
Ex. String temp = word.substring(3);
// returns lo

Question 22

Class that formats decimals

Answer 22

DecimalFormat Class

Question 23

Import for the DecimalFormat Class

Answer 23

import java.text.DecimalFormat;

Question 24

How to format a decimal (ex.)

Answer 24

DecimalFormat fmt = new DecimalFormat("0.###"); 
double total = 1.2345
System.out.print(fmt.format(total));
// prints 1.234

Question 25

String method that returns a new string that is identical l with this string except that every oldChar is replaced by newChar

Answer 25

``` String replace(char oldChar, char newChar) Ex. String newWord = word.replace('l','p'); // returns Heppo ```

Question 26

String Method that returns the character at the specified index

Answer 26

``` char charAt(int index) Ex. char letter = word.charAt(1); //returns e ```

Question 27

String Method that returns true if the string has the same characters as str and false if does not

Answer 27

``` boolean equals(String str) Ex. word.equals("hi"); //returns false ```

Question 28

String Method same as .equals() except ignores the case

Answer 28

``` boolean equalsIgnoreCase(String str) Ex. word.equalsIgnoreCase("hello"); //returns true ```

Question 29

Declaration

Answer 29

int x;

Question 30

Instantiate

Answer 30

x = 50;

Question 31

How do you input something?

Answer 31

``` Create a Scanner Scanner scan = new Scanner(System.in); ```

Question 32

Scanner methods

Answer 32

.nextInt() .nextDouble() .nextLine() .next()

Question 33

How to close a scanner

Answer 33

scan.close();

Question 34

A series of characters that represents a special character

Answer 34

Escape Sequence

Question 35

Method creates a random double from [0,1)

Answer 35

Math.random();