array

Question 1

Joins two or more arrays, and returns a copy of the joined arrays

Answer 1

concat()

Question 2

Copies array elements within the array, to and from specified positions

Answer 2

copyWithin()

Question 3

Returns a key/value pair Array Iteration Object

Answer 3

entries()

Question 4

Checks if every element in an array pass a test

Answer 4

every()

Question 5

Fill the elements in an array with a static value

Answer 5

fill()

Question 6

Creates a new array with every element in an array that pass a test

Answer 6

filter()

Question 7

Returns the value of the first element in an array that pass a test

Answer 7

find()

Question 8

Returns the index of the first element in an array that pass a test

Answer 8

findIndex()

Question 9

Calls a function for each array element

Answer 9

forEach()

Question 10

Creates an array from an object

Answer 10

from()

Question 11

Check if an array contains the specified element

Answer 11

includes()

Question 12

Search the array for an element and returns its position

Answer 12

indexOf()

Question 13

Checks whether an object is an array

Answer 13

isArray()

Question 14

Joins all elements of an array into a string

Answer 14

join()

Question 15

Returns a Array Iteration Object, containing the keys of the original array

Answer 15

keys()

Question 16

Search the array for an element, starting at the end, and returns its position

Answer 16

lastIndexOf()

Question 17

Creates a new array with the result of calling a function for each array element

Answer 17

map()

Question 18

Removes the last element of an array, and returns that element

Answer 18

pop()

mutable

Question 19

Adds new elements to the end of an array, and returns the new length

Answer 19

push()

mutable

Question 20

Reduce the values of an array to a single value (going left-to-right)

Answer 20

reduce()

Question 21

Reduce the values of an array to a single value (going right-to-left)

Answer 21

reduceRight()

Question 22

Reverses the order of the elements in an array

Answer 22

reverse()

will mutate the array

Question 23

Removes the first element of an array, and returns that element

Answer 23

shift()

mutable

Question 24

Selects a part of an array, and returns the new array

Answer 24

slice()

Question 25

Checks if any of the elements in an array pass a test

Answer 25

some()

Question 26

Sorts the elements of an array

Answer 26

sort()

mutable

Question 27

Adds/Removes elements from an array

Answer 27

splice()

mutable

Question 28

Converts an array to a string, and returns the result

Answer 28

toString()

Question 29

Adds new elements to the beginning of an array, and returns the new length

Answer 29

unshift()

mutable

Question 30

Returns the primitive value of an array

Answer 30

valueOf()