Deck 8: Arrays

Question 1

When array elements are passed by value, a copy of the value is made and used within the receiving method.

Answer 1

True

Question 2

After you create an array variable, you still need to ____ memory space.

A) create
B) organize
C) reserve
D) dump

Answer 2

C

Question 3

When you create an array variable, memory space is automatically reserved.

Answer 3

False

Question 4

To initialize an array, you use an initialization list of values separated by commas and enclosed within curly braces.

Question 5

When you declare or access an array, you can use any expression to represent the size, as long as the expression is  _____.

A) a variable
B) enclosed in brackets
C) an integer
D) a list

Question 6

When using parallel arrays, if one array has many possible matches, it is most efficient to place the less common items first so that they are matched right away.

Question 7

You can declare an array variable by placing curly brackets after the array name.

Question 8

Since an array name is a reference, you are able to use the = operator for assigning and the == operator for comparisons.

Question 9

When returning an array reference, square brackets are included with the return type in the method header.

Question 10

Languages such as Visual Basic, BASIC, and COBOL use ____ to refer to individual array elements.

A) ( )
B) [ ]
C) { }
D) $

Question 11

Many programmers feel that breaking out of a for loop early disrupts the loop flow and makes the code harder to understand.

Question 12

A(n) ____ is an integer contained within square brackets that indicates one of an array's variables.

A) postscript
B) subscript
C) variable header
D) indicator

Question 13

In Java, boolean array elements automatically are assigned the value ____.

A) null
B) '\u0000'
C) true
D) false

Question 14

When you create an array of objects, each reference is assigned the value ____.

A) null
B) '\u0000'
C) true
D) false

Question 15

When an application contains an array and you want to use every element of the array in some task, it is common to perform loops that vary the loop control variable from 0 to one less than the size of the array.

Question 16

You use a ____ following the closing brace of an array initialization list.

A) .
B) ;
C) :
D) ,

Question 17

When you declare an array name, no computer memory address is assigned to it. Instead, the array variable name has the special value ____, or Unicode value '\u0000'.

A) empty
B) null
C) false
D) zero

Question 18

When you want to determine whether a variable holds one of many valid values, one option is to use a do…while loop to compare the variable to a series of valid values.

Question 19

Providing values for all the elements in an array is called ____ the array.

A) populating
B) declaring
C) filling
D) irrigating

Question 20

When any ____ type ( boolean , char , byte , short , int , long , float , or double ) is passed to a method, the value is passed.

A) array
B) dummy
C) element
D) primitive

Question 21

A ____ array is one with the same number of elements as another, and for which the values in corresponding elements are related.

A) cloned
B) parallel
C) property
D) two-dimensional

Question 22

When you declare int[] someNums = new int[10]; , each element of someNums has a value of ____________________ because someNums is an integer array.

Question 23

Which of the following statements correctly declares and creates an array to hold five double scores values?

A) integer[] scores = new double[5]
B) double[] scores = new integer[5]
C) double[] = new scores[5]
D) double[] scores = new double[5]

Question 24

When you perform a ____, you compare a value to the endpoints of numerical ranges to find the category in which a value belongs.

A) range match
B) sort
C) reference
D) search

Question 25

Individual array elements are ____ by value when a copy of the value is made and used within the receiving method.

A) sorted
B) passed
C) received
D) stored

Question 26

Which of the following statements correctly initializes an array with an initialization list?

A) int[] nums = {2, 4, 8};
B) int[] nums = (2, 4, 8);
C) int nums = [2, 4, 8];
D) int nums() = int{2, 4, 8}

Question 27

If a class has only a default constructor, you must call the constructor using the keyword ____ for each declared array element.

A) default
B) new
C) first
D) object

Question 28

A(n) ____________________ is a named list of data items that all have the same type.

Question 29

A(n) ____ loop allows you to cycle through an array without specifying the starting and ending points for the loop control variable.

A) do…while
B) inner
C) enhanced for
D) enhanced while

Question 30

When any primitive type variable is passed to a method, the _____ is passed.

A) value
B) reference
C) location
D) memory

Question 31

The length ____ contains the number of elements in the array.

A) box
B) field
C) area
D) block

Question 32

Which of the following println statements will display the last myScores element in an array of 10?

A) System.out.println(vals[0]);
B) System.out.println(vals[1]);
C) System.out.println(vals[9]);
D) System.out.println(vals[10]);

Question 33

An instance variable or object field is also called a(n) ____________________ of the object.

Question 34

When any primitive type is passed to a method, the ____________________ is passed.

Question 35

When you declare or access an array, you can use any expression to represent the size, as long as the expression is a(n) ____________________.

Question 36

It is a good programming practice to ensure that a subscript to an array does not fall below zero, causing a(n) ____.

A) array dump
B) runtime error
C) conundrum
D) compiling error

Question 37

When you initialize parallel arrays, it is convenient to use ____ so that the values that correspond to each other visually align on the screen or printed page.

A) tabs
B) indentation
C) spacing
D) dashes

Question 38

In which of the following statements is the value of myVals null ?

A) int myVals = ""
B) int [] myVals;
C) myVals = int[null]
D) int[null] = myVals

Question 39

When a method returns an array reference, you include ____ with the return type in the method header.

A) { }
B) ( )
C) ( (
D) [ ]

Question 40

Comparing a variable to a list of values in an array is a process called ____ an array.

A) validating
B) using
C) checking
D) searching

Question 42

double[] studentScores;
double studentScores[];
Are both of the above statements valid for declaring an array variable? Why or why not?

Question 43

What is different about passing an array to a method rather than passing a primitive type to a method?

Question 44

double[] studentScores = new double[3];
studentScores[0] = 93;
studentScores[1] = 77;
studentScores[2] = 85;
Write a println statement to display the last element of the studentScores array.

Question 45

What is a subscript and how are the array's elements numbered?

Question 46

How can you use the enhanced for loop?

Question 47

Why is the length field a good option when writing a loop that manipulates an array? What programming error is common when attempting to use length as an array method?

Question 48

public class CostArray
{
    public static void main(String[] args)
    {
       double[] costs = new double[3];
       costs[0] = 5.00;
       costs[1] = 7.00;
       costs[2] = 9.00;
       System.out.println(costs[3]);
    }
}
Once the above code is compiled and executed, an error message is generated. Explain the error message that will result and explain the reason for the error.

Question 49

When working with arrays, why is it beneficial to use a loop with a declared constant equal to the size of the array?

Question 50

How would a programmer perform a range match when writing an application that takes into consideration different discount rates for customers? Give an example.

Question 51

How would you use a method that belongs to an object that is part of the array? Use an example and demonstrate with Java code.

Question 52

When using an array with all elements used, why would a programmer use a loop control variable from 0 to one less than the size of the array? Give an example.

Question 53

Why would you use spacing when initializing parallel arrays?

Question 54

When populating an array with an initialization list, you do not need to use the new keyword or provide an array size. Explain why this is the case.

Question 55

What does an array's name represent and what value does it hold when declared?

Question 56

Write the statement to declare an array of integers that will hold studentScores .

Question 57

Describe a situation in which storing just one value at a time in memory does not meet your needs.

Question 58

Using just one statement, declare and create an array that will reserve memory locations for 10 scores values that are type double .

Question 59

public static int[] sampleArray()
{
    int studentScores = {72, 91, 83};
    ____
}
Using the above code, write the statement that will return the array name.

Question 60

String[] countyNames = {"Clark", "Delaware", "Madison"};
What will be the value of countyNames[0].length() , countyNames[1].length() , and countyNames[2].length() ?

Question 61

While you can provide any legal identifier you want for an array, conventional rules are typically followed. List and describe the naming conventions for naming arrays.

Question 62

int[] multsOfTen = {10, 20, 30, 40, 50, 60};
The above code creates an array named multsOfTen . Describe how array sizes are determined when using an initialization list and how memory is assigned.

Question 63

String[] countyNames = {"Clark", "Delaware", "Madison"};
Using the above statement, what will be the value of countyNames[0] , countyNames[1] , and countyNames[2] ?

Question 64

The following statement declares an array:
int[] scoreArray = {2, 14, 35, 67, 85};
final int INCREASE = 3;
Create a loop that will add INCREASE to every array element. Use the length field in the loop that will contain the number of elements in the array.

Question 65

Write the statement to create an array named studentScores that will store five integer value student scores. Initialize the array using an initialization list with the values 70, 85, 92, 67, and 76.

Question 66

Write the statement to declare an array variable named studentScores with type double . Write a second statement to create an array of 10 objects of type double .