Array Methods and Properties

Question 1

[ _ ]

What does the above do in Javascript?

Answer 1

creates a new array

Question 2

new Array()

What does the above do in Javascript?

Answer 2

creates a new array

Question 3

at()

What does the above do in Javascript?

Answer 3

returns an indexed element of an array

Question 4

concat()

What does the above do in Javascript?

Answer 4

joins arrays and returns an array with the joined arrays

Question 5

constructer

What does the above do in Javascript?

Answer 5

returns the function that created the Array prototype

Question 6

copyWithin()

What does the above do in Javascript?

Answer 6

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

Question 7

entries()

Answer 7

Returns a key/value pair Array Interation Object

Question 8

every()

What does the above do in Javascript?

Answer 8

checks if every element in an array pass a test

Question 9

fill()

What does the above do in Javascript?

Answer 9

fills the element in an array with a static value

Question 10

filter()

What does the above do in Javascript?

Answer 10

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

Question 11

find()

What does the above do in Javascript?

Answer 11

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

Question 12

findIndex()

What does the above do in Javascript?

Answer 12

returns the index of the first element in an array that passes a test

Question 13

findLast()

What does the above do in Javascript?

Answer 13

returns the value of the last element in an array that pass a test

Question 14

fineLastIndex()

What does the above do in Javascript?

Answer 14

returns the index of the last element in an array that pass a test

Question 15

flat()

What does the above do in Javascript?

Answer 15

concatenation sub-array elements

Question 16

flatMap()

What does the above do in Javascript?

Answer 16

maps all array elements and creates a new flat array

Question 17

forEach()

What does the above do in Javascript?

Answer 17

calls a function for each array element

Question 18

from()

What does the above do in Javascript?

Answer 18

creates an array from an object

Question 19

from()

What does the above do in Javascript?

Answer 19

creates an array from an object

Question 20

includes()

What does the above do in Javascript?

Answer 20

check if an array contains the specified element

Question 21

indexOf()

What does the above do in Javascript?

Answer 21

search the array for an element and returns its position

Question 22

isArray()

What does the above do in Javascript?

Answer 22

checks whether an object is an array

Question 23

join()

What does the above do in Javascript?

Answer 23

joins all element of an array into a string

Question 24

keys()

What does the above do in Javascript?

Answer 24

returns an Array Interation Object, containing the keys of the original array

Question 25

lastIndexOf() What does the above do in Javascript?

Answer 25

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

Question 26

length What does the above do in Javascript?

Answer 26

sets or returns the number of elements in an array

Question 27

map() What does the above do in Javascript?

Answer 27

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

Question 28

of() What does the above do in Javascript?

Answer 28

creates an array from a number of arguements

Question 29

pop() What does the above do in Javascript?

Answer 29

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

Question 30

prototype What does the above do in Javascript?

Answer 30

allows you to add properties to an Array object

Question 31

push() What does the above do in Javascript?

Answer 31

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

Question 32

reduce() What does the above do in Javascript?

Answer 32

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

Question 33

reduceRight() What does the above do in Javascript?

Answer 33

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

Question 34

reverse() What does the above do in Javascript?

Answer 34

reverses the order of the elements in an array

Question 35

shift() What does the above do in Javascript?

Answer 35

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

Question 36

slice() What does the above do in Javascript?

Answer 36

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

Question 37

some() What does the above do in Javascript?

Answer 37

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

Question 38

sort() What does the above do in Javascript?

Answer 38

sorts the elements of an array

Question 39

splice() What does the above do in Javascript?

Answer 39

adds or removes array elements

Question 40

toReversed() What does the above do in Javascript?

Answer 40

reversed the order of array elements (to a new array)

Question 41

toSorted() What does the above do in Javascript?

Answer 41

sorts the elements of an array (to a new array)

Question 42

toSpliced() What does the above do in Javascript?

Answer 42

adds or removes array elements (to a new array)

Question 43

toString() What does the above do in Javascript?

Answer 43

converts an array to a string, and returns the results

Question 44

unshift() What does the above do in Javascript?

Answer 44

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

Question 45

valueOf() What does the above do in Javascript?

Answer 45

returns the primitive value of an array

Question 46

with() What does the above do in Javascript?

Answer 46

Return a new array with updated elements