Deck 6: Working With Collections of Data

Question 1

Every item stored within a hash is assigned both a key as well as a unique index position.

Answer 1

False

Question 2

An array is an indexed collection of key-value pairs.

Answer 2

False

Question 3

Unlike other types of Ruby objects, you cannot create a new array using the new method.

Answer 3

False

Question 4

Like most other programming languages, Ruby requires that an array be declared in advance of its use.

Question 5

Unlike arrays, hashes are limited to storing only numeric and string data.

Question 6

The Array class's shift method can be used to delete the first item in an array.

Question 7

An easy way to determine if a hash contains any key-value pairs is to execute the full? method.

Question 8

The Array class's insert_at is the opposite of the delete_at method.

Question 9

The Array class's last method can be used to retrieve the first or last item from an array.

Question 10

The clear method can be used to remove all key-value entries from a hash.

Question 11

The reverse method can be used to generate a list of array items in the opposite order that they are actually stored.

Question 12

The Hash class's delete method can be used to remove a key-value pair based on a supplied key.

Question 13

Ruby requires that the size of an array be specified when the array is defined.

Question 14

Although the each loop can be used to process the content of an array, you are generally better off using a while or until loop.

Question 15

Values stored within an array are referenced based on their index position within the array.

Question 16

An array's index begins at 0 and is incremented by one each time a new item it added.

Question 17

The push and pop methods are used to add new items to the end of an array.

Question 18

The Array class's pop method is used to delete an item from the end of an array.

Question 19

The slice method can be used to retrieve a range of value from an array.

Question 20

As arrays grow in size it takes more and more time to process and retrieve array items.

Question 21

Ruby arrays start with an index position of ____?

A) 0
B) 1
C) 2
D) -1

Question 22

Which of the following methods can be used to retrieve the last array item?

A) midlle
B) at
C) last
D) first

Question 23

Which of the following methods can be used to retrieve a series of items from an array?

A) range
B) mode
C) slice
D) range?

Question 24

Which of the following methods can be used to determine if an array contains any items.

A) empty?
B) nothing?
C) full?
D) None of the above

Question 25

The inspect method can be used to convert the contents of a hash into an array and vice versa.

Question 26

In addition to variables, Ruby also permits the storage of collections of data using which of the following constructs?

A) Arrays and Hashes
B) Lists and Collections
C) Variables and Constants
D) None of the above

Question 27

Which of the following methods can be used to retrieves the first element stored in an array?

A) first
B) @
C) in
D) None of the above

Question 28

Ruby permits the specification of a negative integer value when referring to array values. An index value of -2 would refer to which item in an array?

A) The first item stored in the array
B) The second item stored in the array
C) The last item stored in the array
D) The second to last item stored in the array

Question 29

Which of the following methods can be used to retrieve an array item based on its index position?

A) @
B) at
C) #
D) in

Question 30

Which of the following methods allows you to delete an array item based on its value?

A) value
B) remove
C) delete
D) None of the above

Question 31

Which of the following statements is not valid?

A) cars = Array.new
B) cars = %w(Pinto Corvette Viper)
C) cars = ["Pinto", "Corvette", "Viper"]
D) None of the above

Question 32

Which of the following methods automatically iterates once for each item stored in an array?

A) each
B) while
C) until
D) next

Question 33

Which of the following options can be used to determine if an array contains any values?

A) Use the Array class's size method
B) Use the Array class's empty? method
C) Use the Array class's length method
D) All of the above

Question 34

The following statement is an example of chaining methods together. fruit.sort.reverse.inspect

Question 35

Which of the following methods can be used to remove all of the items from an array?

A) empty
B) remove
C) delete
D) clear

Question 36

You can use the Hash class's hash method to generate a list of all of the keys stored in a hash.

Question 37

As a hash grows in size it takes more and more time to process and retrieve hash key-item pairs.

Question 38

Taking the output of one method and using it as input for a subsequent method is accomplished through a process referred to as ____ the two methods together.

A) appending
B) chaining
C) binding
D) linking

Question 39

Ruby permits the use of both real number and integers as index position values.

Question 40

Which of the following loops can be used to process the contents of an array?

A) while
B) each
C) until
D) All of the above

Question 41

Which of the following methods can be used to generate a list of hash keys?

A) list
B) keys
C) hash
D) All of the above

Question 42

In contrast to an array, the time it takes to retrieve data from a hash ____ as the hash grows in size.

A) is greater
B) is less
C) is about the same
D) varies back on the type of data stored

Question 43

What is a collection of key-value pairs called?

A) Associative Array
B) Dictionary
C) Hash
D) All of the above

Question 44

What happens if you accidentally assign a new value to a hash using a key that already exists?

A) The new value replaces the previous values
B) The original value is retained and the new value is disregarded
C) An error occurs and your script stops executing
D) None of the above

Question 45

Which of the following methods can be used to conditionally delete key-value pairs from a hash?

A) delete
B) delete_at
C) delete_if
D) remove

Question 46

One way of creating a new hash is to take the contents of two existing hashes and combine them together using the _______________ method.

A) combine
B) append
C) merge
D) None of the above