Array Methods

Question 1

What will the following array method return?

famous_cats = [“lil’ bub”, “grumpy cat”, “Maru”]

famous_cats.include?(“Maru”)

Answer 1

True

Question 2

How would you create the following array without hardcoding?

[1, 2, 3, 4, 5]

Answer 2

(1..5).to_a

Question 3

How would I check to see if the array included “lil bub”?

famous_cats = [“lil’ bub”, “grumpy cat”, “Maru”]

Answer 3

famous_cats.include?(“lil bub”)

Should return true

Question 4

How would I check to see the number of elements in an array? (There are two ways)

famous_cats = [“lil’ bub”, “grumpy cat”, “Maru”]

Answer 4

famous_cats.size
OR
famous_cats.length

Question 5

How would you create a new array called my_array using the class constructor?

Answer 5

my_array = Array.new

Question 6

How would you grab the index of “Maru”?

famous_cats = [“lil’ bub”, “grumpy cat”, “Maru”]

Answer 6

famous_cats.index(“Maru”)

Question 7

How would you insert the item “nala cat” at the beginning of the array?

famous_cats = [“lil’ bub”, “grumpy cat”, “Maru”]

Answer 7

famous_cats.unshift(“nala cat”)

Question 8

How would you create a new array called my_array using the literal constructor?

Answer 8

my_array = [ ]

Question 9

What will the following array method return?

famous_cats = [“lil’ bub”, “grumpy cat”, “Maru”]

famous_cats.length

Answer 9

3

Question 10

How would you retrieve the first item of an array? (There are two ways)

famous_cats = [“lil’ bub”, “grumpy cat”, “Maru”]

Answer 10

famous_cats.first
OR
famous_cats[0]

Question 11

What will the following array method return?

(1..10).to_a

Answer 11

[1, 2, 3, 4, 5, 6, 7, 8, 9, 10]

Question 12

How would you make the array [“a”, “b”, “c”] looking like the following?

“a.b.c”

Answer 12

[“a”, “b”, “c”].join(“.”)

Question 13

What will the following array method return?

[“a”, “b”, “c”].join

Answer 13

“abc”

Question 14

How would you retrieve the second item in the array famous_cats?

famous_cats = [“Cheshire Cat”, “Puss in Boots”, “Garfield”]

Answer 14

famous_cats[1]

Question 15

What will the following array method return?

famous_cats = [“lil’ bub”, “grumpy cat”, “Maru”]

famous_cats.last

Answer 15

“Maru”

Question 16

What will the following array method return?

famous_cats = [“lil’ bub”, “grumpy cat”, “Maru”]

famous_cats.index(“grumpy cat”)

Answer 16

1

Question 17

What will the following array method return?

famous_wizards = [“Dumbledore”, “Gandalf”, “Merlin”]

famous_wizards.reverse

Answer 17

[“Merlin”, “Gandalf”, “Dumbledore”]

Question 18

What will the following array method return?

famous_cats = [“lil’ bub”, “grumpy cat”, “Maru”]
famous_cats.include?(“Garfield”)

Answer 18

False

Question 19

How would you insert the item “nala cat” at the end of the array? (There are two ways)

famous_cats = [“lil’ bub”, “grumpy cat”, “Maru”]

Answer 19

famous_cats &laquo_space;“nala cat”
OR
famous_cats.push(“nala cat”)

Question 20

How would you sort the following array?

famous_cats = [“lil’ bub”, “grumpy cat”, “Maru”]

Answer 20

famous_cats.sort

Question 21

How would you remove the last item of the array?

famous_cats = [“lil’ bub”, “grumpy cat”, “Maru”]

Answer 21

famous_cats.pop

Question 22

What will famous_cats look like after the code finishes running?

famous_cats = [“lil’ bub”, “grumpy cat”, “Maru”]

famous_cats.pop

Answer 22

[“lil’ bub”, “grumpy cat”]

Question 23

What will famous_cats look like after the code finishes running?

famous_cats = [“lil’ bub”, “grumpy cat”, “Maru”]

famous_cats &laquo_space;“nala cat”

Answer 23

[“lil’ bub”, “grumpy cat”, “Maru”, “nala cat”]

Question 24

What will the following array method return?

famous_cats = [“lil’ bub”, “grumpy cat”, “Maru”]

famous_cats.size

Answer 24

3

Question 25

What will the following array method return?

[“a”, “b”, “c”].join(“ “)

Answer 25

“a b c”

Question 26

How would you retrieve the last item of an array?

famous_cats= [“lil’ bub”, “grumpy cat”, “Maru”]

Answer 26

famous_cats.last

Question 27

What will famous_cats look like after the code finishes running?

famous_cats = [“lil’ bub”, “grumpy cat”, “Maru”]

famous_cats.shift

Answer 27

[“grumpy cat”, “Maru”]

Question 28

How would you reverse the following array?

famous_wizards = [“Dumbledore”, “Gandalf”, “Merlin”]

Answer 28

famous_wizards.reverse

Question 29

What will the following array method return?

famous_cats = [“lil’ bub”, “grumpy cat”, “Maru”]

famous_cats.sort

Answer 29

[“grumpy cat”, “lil’ bub”, “Maru”]

Question 30

What will the following array method return?

famous_cats = [“lil’ bub”, “grumpy cat”, “Maru”]

famous_cats.first

Answer 30

“lil bub”

Question 31

What will the following array method return?

famous_cats = [“lil’ bub”, “grumpy cat”, “Maru”]

famous_cats.index(“Garfield”)

Answer 31

nil

Question 32

What will famous_cats look like after the code finishes running?

famous_cats = [“lil’ bub”, “grumpy cat”, “Maru”]

famous_cats.push(“nala cat”)

Answer 32

[“lil’ bub”, “grumpy cat”, “Maru”, “nala cat”]

Question 33

What will famous_cats look like after the code finishes running?

famous_cats = [“lil’ bub”, “grumpy cat”, “Maru”]

famous_cats.unshift(“nala cat”)

Answer 33

[“nala cat”, “lil’ bub”, “grumpy cat”, “Maru”]