Deck 10: Exploring Arrays Loops and Conditional Statements Tutorial

Question 1

Increasing the value of the length property adds more items to an array, but the items have null values until they are defined.

Answer 1

True

Question 2

A command block is indicated by its opening and closing square brackets [ ].

Answer 2

False

Question 3

By default, items are placed in an array either in the order in which they are defined or explicitly by index number.

Answer 3

True

Question 4

The getDate() method in a calendar app returns an integer ranging from 0 (Sunday) to 6 (Saturday).

Question 5

The break statement runs a command or a command block only if the conditional expression returns the value true ; it does nothing if the condition is false.

Question 6

The appearance of any form element can be changed by modifying style sheets instead of the JavaScript code.

Question 7

When a pass statement is encountered, control is passed to the statement immediately following it.

Question 8

The do/while loop is generally used when the program loop should run at least once before testing for the stopping condition.

Question 9

In an if loop, a variable known as a counter variable is used to track the number of times a block of commands is run.

Question 10

A calendar that is created as a web table can have class and ID designations to make it easy for page developers to assign different styles to different parts of the calendar.

Question 11

Statement labels are used to identify statements in JavaScript code so that the statements can be referenced elsewhere in a program.

Question 12

The every(callback [, thisArg]) array method applies the callback function to each item in an array.

Question 13

In an array literal, the array values are a space-separated list within a set of curly brackets.

Question 14

The slice() method reverses the order of items in an array, making the last items first and the first items last.

Question 15

T he value of the length property can be reduced without removing items from an array.

Question 16

The map(callback [, thisArg]) method returns the index of the first element in the array that passes a test in the callback function.

Question 17

Index values start with 1 so that the initial item in an array has an index value of 1, the second item has an index value of 2, and so on.

Question 18

JavaScript supports logical operators that connect several expressions.

Question 19

When each entry in an array matches the entry in another array, it is called a linear array.

Question 20

The while statement is used to exit a program loop before the stopping condition is met.

Question 21

What is the output of the following code? for(var i = 5; i > 0; i--)

A) i = 4, 3, 2, 1, 0
B) i = 5, 4, 3, 2, 1
C) i = 0, 1, 2, 3, 4
D) i = 1, 2, 3, 4, 5

Question 22

A _____, which employs the first-in-first-out (FIFO) principle in which the first item added to the data list is the first removed, is similar to a stack.

A) frame
B) bitmap
C) queue
D) binary tree

Question 23

Which of the following examples tests whether x is equal to 5 or y is equal to 8?

A) (x === 5) && (y === 8)
B) (x === 5) : (y === 8)
C) (x === 5) || (y === 8)
D) (x === 5) / (y === 8)

Question 24

Identify the expression used to reference array values.

A) array()
B) array [ i ]
C) array { array1 , array2 ,…}
D) array:: values

Question 25

Identify a method that is used to create a subarray.

A) concat()
B) slice()
C) assert()
D) sort()

Question 26

Identify a compare function that sorts numeric values in ascending order.

A) function ascending(a, b) { return a - b; }
B) function ascending(b, a) { return a; }
C) function ascending(a, b) { return b - a; }
D) function ascending(b, a) { return b; }

Question 27

Identify the general structure of a for loop.

A) for ( start ; continue ; update ) { commands }
B) for ( start ; update) { commands }
C) for ( start ; stop ) { commands }
D) for ( start ; stop ; continue ) { commands }

Question 28

What is the output of the following code? for (var i = 0; i

A) i = 0, 60, 120, 180, 240, 360
B) i = 360, 240, 180, 120, 60, 0
C) i = 60, 120, 240, 480, 960
D) i = 600, 300, 240, 180, 120, 60

Question 29

A(n) _____ is a collection of values organized under a single name.

A) index
B) heap
C) array
D) tuple

Question 30

Numeric data can be sorted by creating a(n) _____ function that contrasts the values of two adjacent array items.

A) sum
B) iteration
C) assert
D) compare

Question 31

Identify a compare function that sorts numeric values in descending order.

A) function descending(a, b) { return a - b; }
B) function descending(b, a) { return b; }
C) function descending(a, b) { return b - a; }
D) function descending(b, a) { return a; }

Question 32

The _____ loop tests the condition to continue the loop right after the latest command block is run.

A) do/while
B) while
C) for
D) forEach

Question 33

Identify the syntax of the while loop.

A) while ( continue ) { commands }
B) while ( start ) { commands }
C) while [ start;stop ] { commands }
D) while [ update ; continue ] { commands }

Question 34

Identify the output of the following code. var x = [3, 45, 1234, 24]; x.sort();

A) 1234, 24, 3, 45
B) 3, 24, 45, 1234
C) 1234, 45, 24, 3
D) 1234, 24, 45

Question 35

The _____ operator tests whether two items are equal in value and have the same data type.

A) = =
B) = = =
C) =
D) !=

Question 36

Identify a method that inserts new items at the front of an array.

A) reverse()
B) unshift()
C) assert()
D) sort()

Question 37

Identify the general syntax of the do/while loop.

A) do ( continue ) { commands } while ( continue ){ commands }
B) while ( continue ) { commands } do ( continue ){ commands }
C) while { commands } do ( continue );
D) do { commands } while ( continue );

Question 38

For array data that should be treated as a queue, the _____ method is used, which is similar to the pop() method except that it removes the first array item and not the last.

A) reverse()
B) shift()
C) assert()
D) sort()

Question 39

What is the output of the following code? var x = ["a", "b", "c"]; x.push("d", "e"); x.pop(); x.pop();

A) x = ["a", "b", "c"]
B) x = ["a", "b", "d", "e"]
C) x = ["d", "e"]
D) x = ["c", "d", "e"]

Question 40

Which of the following determines the current size of an array?

A) array (length)
B) array [length]
C) array .length
D) array ::length

Question 41

The _____ method performs an action similar to the forEach() method except that the function it calls returns a value that can be used to match the contents of an existing array into a new array.

A) sort()
B) map()
C) splice()
D) find()

Question 42

Identify the structure of an if statement

A) if (condition) { commands }
B) if { }(condition)
C) if { commands }
D) if { } (condition){ commands

Question 43

Which of the following statements is used to terminate any program loop or conditional statement?

A) for
B) while
C) pass
D) break

Question 44

Which of the following functions increases the value of each item in an array by 1?

A) sum()
B) AddArray()
C) StepUp()
D) ceil()

Question 45

Identify a true statement of array .find( callback [, thisArg ]) method.

A) It tests whether the condition returned by the callback function holds for at least one item in array .
B) It returns the value of the first element in the array that passes a test in the callback function.
C) It tests whether the condition returned by the callback function holds for all items in array .
D) It returns the index of the first element in the array that passes a test in the callback function.

Question 46

What is the output of the following code? var x = [4, 7, 11]; x.forEach(stepUp); function stepUp(value, i, arr) { arr[i] = value + 1; }

A) 4, 7, 11
B) 3, 7, 11
C) 5, 8, 12
D) 8, 14, 22

Question 47

Which of the following methods is used to determine the day of the week on which a month starts?

A) calDay;
B) day.calDay()
C) find.Day;
D) getDay()

Question 48

What is the output of the following code? var sum = 0; var x = [1, 3, 7, 11]; x.forEach(sumArray); function sumArray(value) { sum += value; }

A) 0
B) 231
C) 11
D) 22

Question 49

Identify the expression in which the initial value of the day variable will be set to match the first day of the calendar month.

A) var day = Date(calDate(), calDate.getDay(), 1);
B) var day = new Day(calDate.getDD(), calDate.getMM(),calDate.getYY(),1);
C) var day = new Day(calDay.getFullMonth(), calDay.getDate(), 1);
D) var day = new Date(calDate.getFullYear(), calDate.getMonth(), 1);

Question 50

Which of the following values will the expression 15 % 4 return?

A) 1
B) 11
C) 3
D) 60

Question 51

The _____ method creates a new array by passing the original array items to the callback function, which returns the equivalent value of the array items.

A) array .every( callback [, thisArg ])
B) array .map( callback [, thisArg ])
C) array .some( callback [, thisArg ])
D) array .find( callback [, thisArg ])

Question 52

Identify the general syntax of the forEach method.

A) array.forEach [, thisArg ]() { commands }
B) array.forEach( callback [, thisArg ])
C) array.forEach ( value ){ commands }
D) array.forEach( callback [ value ])

Question 53

Identify a method that extracts array items that match a specified condition.

A) sort()
B) filter()
C) splice()
D) reverse()

Question 54

Which of the following methods creates a new array populated with the elements of array that return a value of true from the callback function?

A) array .every( callback [, thisArg ])
B) array .filter( callback [, thisArg ])
C) array .some( callback [, thisArg ])
D) array .find( callback [, thisArg ])

Question 55

Identify a method that tests whether the condition returned by the callback function holds for all items in an array .

A) array .every( callback [, thisArg ])
B) array .filter( callback [, thisArg ])
C) array .some( callback [, thisArg ])
D) array .find( callback [, thisArg ])

Question 56

What is the output of the following code? var scores = [92, 68, 83, 95, 91, 65, 77]; var highScores = scores.filter(gradeA); function gradeA(value) { return value > 90; }

A) [92, 95, 91]
B) [96, 97, 98]
C) [68, 83, 65, 77]
D) [91, 92, 65, 68, 77, 83]

Question 57

Identify a method that decreases array by keeping only those items that return a value of true from the callback function.

A) array .every( callback [, thisArg ])
B) array .map( callback [, thisArg ])
C) array .reduce( callback [, thisArg ])
D) array .find( callback [, thisArg ])

Question 58

Identify the general structure for accessing each value from an array using a for loop.

A) for ( i array ; i ++) { commands involving array [ i ] }
B) for (var i = 0; i ++; i array .length) { commands involving array ( i) }
C) for (var i = 0; i ++) { commands involving array ( i) }
D) for (var i = 0; i array .length; i ++) { commands involving array [ i ] }

Question 59

The _____ method diminishes array from the last element by keeping only those items that return a value of true from the callback function.

A) array .every( callback [, thisArg ])
B) array .map( callback [, thisArg ])
C) array .reduceRight( callback [, thisArg ])
D) array .findIndex( callback [, thisArg ])

Question 60

Identify a true statement of array .some( callback [, thisArg ]) method.

A) It tests whether the condition returned by the callback function holds for at least one item in array .
B) It returns the value of the first element in the array that passes a test in the callback function.
C) It tests whether the condition returned by the callback function holds for all items in array .
D) It returns the index of the first element in the array that passes a test in the callback function.

Question 62

Case-Based Critical Thinking Questions Case 9-2 Gregor, a software developer, is developing a calendar application. He has to use several if conditional statements to ensure that the calendar displays the exact number of days present in each month of each year. He creates a dayCount array to keep track of the number of days in each month. Gregor wants to create a condition to ensure that all the years divisible by 4 should contain 29 days in February. Which of the following statements should he use?

A) if (thisYear % 4 === 0) { dayCount[1] = 29; }
B) if (this year/4 === 0) { dayCount[2] = 29; }
C) if (this year*4==0) { dayCount[1] = 29 }
D) if (thisYear % 4 dayCount[2] = 29; }

Question 64

Case-Based Critical Thinking Questions Case 9-1 Melissa, a computer science engineering student, is learning the basics of programming by exploring arrays. She learns about different array methods. She wishes to learn more on inserting and deleting array items. She creates monthName array to extract only the three spring months-March, April, and May-from a calendar. Melissa wants to extract the spring months and store them in the monthName array. Identify a method Melissa should choose to perform this task.

A) springMonths = monthName.slice(2, 5);
B) springMonths = monthName.splice(2, 3);
C) springMonths = monthName.slice(3, 5);
D) springMonths = monthName.splice(5, 3);

Question 66

Describe the structure of the if else statement.

Question 67

The _____ statement stops processing the commands in the current iteration of the loop and proceeds to the next iteration instead of stopping the program loop altogether.

A) switch
B) else
C) continue
D) pass

Question 68

Case-Based Critical Thinking Questions Case 9-2 Gregor, a software developer, is developing a calendar application. He has to use several if conditional statements to ensure that the calendar displays the exact number of days present in each month of each year. He creates a dayCount array to keep track of the number of days in each month. Gregor wants to ensure February contains 29 days only in the year 2020 as it is a leap year. Which of the following should Gregor use to set the value in the dayCount array?

A) if (thisYear === 2020) { dayCount[1] = 29; }
B) if (dayCount=29) { 2020; }
C) if { thisYear = 2020; dayCount[1] == 29; }
D) if { dayCount=29 && this year=2020; }

Question 69

Briefly explain the process of using arrays as data stacks.

Question 70

Explain the length property of an array with examples.

Question 71

Case-Based Critical Thinking Questions Case 9-1 Melissa, a computer science engineering student, is learning the basics of programming by exploring arrays. She learns about different array methods. She wishes to learn more on inserting and deleting array items. She creates monthName array to extract only the three spring months-March, April, and May-from a calendar. Melissa wants to remove spring months from the monthName array. Which of the following methods should Melissa use?

A) springMonths = monthName.slice(2, 5);
B) springMonths = monthName.splice(2, 3);
C) springMonths = monthName.slice(3, 5);
D) springMonths = monthName.splice(5, 3);

Question 72

Case-Based Critical Thinking Questions Case 9-1 Melissa, a computer science engineering student, is learning the basics of programming by exploring arrays. She learns about different array methods. She wishes to learn more on inserting and deleting array items. She creates monthName array to extract only the three spring months-March, April, and May-from a calendar. Melissa wants to insert abbreviations of spring months into the monthName array. Which of the following methods should she use?

A) monthName.reverse(5, 3, "Mar", "Apr", "May");
B) monthName.sort(2, 3, "Mar", "Apr", "May");
C) monthName.join(5, 3, "Mar", "Apr", "May");
D) monthName.splice(2, 3, "Mar", "Apr", "May");

Question 73

Identify the syntax of the statement label.

A) label = {statements}
B) statement!(label)
C) label: statements
D) statements.label