Cs 159 Exam 2

Front 1

array

Back 1

an object that can store a group of values all of the same type

Front 2

size declarator

Back 2

number inside the brackets when you declare an array

Front 3

once an array is created

Back 3

the size of the array can not be changed

Front 4

subscript

Back 4

used as an index to pinpoint a specific element within an array

Front 5

bounds checking occurs at

Back 5

runtime

Front 6

if an array is out of bounds

Back 6

an exception is thrown and immediately terminates

Front 7

length field

Back 7

contains the number of elements in an array

Front 8

largest subscript

Back 8

in an array is length-1

Front 9

enhanced for loop

Back 9

designed to iterate once for every element in an array, each time the loop iterates it copies an array element to a variable

Front 10

for(int val: Numbers)

System.out.println(val);

what is the purpose of val?

Back 10

it receives the value of the array element temporarily each time the loop iterates

Front 11

array1 == array2

Back 11

does not copy the array, makes a copy of the address that is stored in array 1

Front 12

reference copy

Back 12

when two variables reference the same array

Front 13

to copy an array

Back 13

you need to copy each individual element of the array

Front 14

when passing an array to a method

Back 14

it is passed just as an object is, actual array is not passed but a reference to the array is

Front 15

ture or false, arr1 == arr2

Back 15

always will be false because they have 2 different memory addresses

Front 16

when a partially filled array is passedc as an argument to a method

Back 16

the variable that holds the count of items must also be passed as an argument

Front 17

an array of string objects

Back 17

is really an array of references to string objects

Front 18

sequential search algorithm

Back 18

compares each element w/ the value being searched for and stops when the value is found

Front 19

2d array

Back 19

an array of arrays composed of rows and columns

Front 20

int[][] numbers = { {1, 2, 3} {4, 5, 6} {7, 8, 9}};

numbers.length equals?

Back 20

3( # of rows)

Front 21

ragged array

Back 21

when rows of a 2d array are different lengths

Front 22

selection sort algorithm

Back 22

smallest value in an array is located and moved to element 0, switching with the element that was stored there

Front 23

ArrayList

Back 23

an object that is an array of objects

Front 24

to add items to arraylist

Back 24

arraylist.add("James");

Front 25

to get the number of items stored in arraylist

Back 25

arraylist.size();

Front 26

default capacity of arraylist

Back 26

10, without changing it manually

Front 27

given an array named x, a reference to x[x.length]

Back 27

causes an indexoutofboundsexception

Front 28

how many bytes if each reference is 4?

int[] a = new int[10];

int[b] = a;

Back 28

48

Front 29

an enhanced for loop

Back 29

cannot be used to change array elements

Front 30

arraylist size and capacity

Back 30

size <= capacity

Front 31

to reference the last element of arraylist

Back 31

list.get(list.size() - 1)

Front 32

Wrapper class

Back 32

a class that is wrapped around a primitive data type and allows you to create objects instead of variables

Front 33

immutable

Back 33

once an object is created value can not be changed

Front 34

tokenizing

Back 34

the process of breaking a string down into components(tokens)

Front 35

delimeter

Back 35

character that separates tokens

Front 36

split

Back 36

tokenizes a string and returns an array of string objects

Front 37

input file

Back 37

file that a program reads data from, serves as input to the program

Front 38

output file

Back 38

file that a program writes data to, program stores output

Front 39

text file

Back 39

contains data that has been encoded as tet using unicode

Front 40

binary file

Back 40

contains data that has not been converted to text

Front 41

printWriter

Back 41

a class that allows you to open a file for writing

Front 42

printWriter outputFile = new PrintWriter("Data.txt");

Back 42

passes the name of the file you want to open

Front 43

if the file you are opening already exists

Back 43

it will be erased an an empty file with the same name will be created

Front 44

outputFile.close();

Back 44

closes file when done writing, writes any unsaved data remaining in the file buffer

Front 45

buffer

Back 45

a small holding section of memory when it is filled all the memory that is stored there is written to the file

Front 46

exception

Back 46

a signal indicating that the program cannot continue until the unexpected even has been dealt with

Front 47

fileWrtier

Back 47

used to append data to an existing file

Front 48

binary file

Back 48

a file that contains data that is not readable in text form is called a(n)

Front 49

printwriter

Back 49

The best class to use for writing a file is

Front 50

Every output file should be explicitly closed after the last write operation so that

Back 50

the buffer will be written out to the file

Front 51

IOException

Back 51

When an error occurs during file output, the program will thrown a(n)

Front 52

PrintWriter output = new PrintWriter(new FileWriter(“filename.txt”, true));

Back 52

The correct way to open a file for extension (to append to the file) is:

Front 53

/home/username/myfile.txt

Back 53

The correct form in which to specify a file on a Unix system is

Front 54

C:\\Users\\username\\myfile.txt

Back 54

the correct form in which to specify a file on a Windows system is

Front 55

The correct way to open a file to be read using Scanner is

Back 55

Scanner input = new Scanner(new File(“filename.txt”));

Front 56

if (inputFile.exists()) {…}

Back 56

The Scanner method to detect whether a file exists is

Front 57

while (inputFile.hasNext()) {…}

Back 57

The correct way to setup an input loop with Scanner is