Array Method 2s Pt

Question 1

from()

Answer 1

Create an array from any iterable object.

Question 2

includes ()

Answer 2

Checks for specified value in an array, returns a boolean, case sensitive

Question 3

indexOf()

Answer 3

returns the first index (position) of a specified value.

returns -1 if the value is not found.

starts at a specified index and searches from left to right.

Question 4

isArray()

Answer 4

returns true if an object is an array, otherwise false

Question 5

join()

Answer 5

returns an array as a string, does not change the original array.

Question 6

keys()

Answer 6

returns an Array Iterator (loopable) object with the keys of an array

Question 7

length

Answer 7

sets or returns the number of elements in an array.

Question 8

lastIndexOf()

Answer 8

Returns the last index of a specified value

returns -1 if the value is not found.

starts at a specified index and searches from right to left.

Question 9

map()

Answer 9

calls a function once for each element in an array and create a new array with the results

Question 10

pop()

Answer 10

removes the last value of the array
changes the original array
returns the removed element

Question 11

prototype

Answer 11

allows you to add new properties and methods to arrays.

Question 12

push()

Answer 12

adds an element to the end of the array

Question 13

reduce()

Answer 13

executes a reducer function for array element. (add & subtract)

returns a single value: the function’s accumulated result.

Question 14

reduceRight()

Answer 14

executes a reducer function for each array element.

works from right to left.

returns a single value: the function’s accumulated result.

Question 15

reverse()

Answer 15

reverses the order of the elements in an array.

overwrites the original array.

Question 16

shift()

Answer 16

removes the first value in an array and assigns it to a variable

Question 17

slice()

Answer 17

returns selected elements in an array, as a new array.

selects from a given start, up to a (not inclusive) given end

Question 18

some()

Answer 18

checks if any array elements pass a test (provided as a function)

method executes the function once for each array element

If the function returns true, some() returns true and stops.
If the function returns false, some() returns false and stops.

Question 19

sort()

Answer 19

sorts the elements of an array in alphabetical and ascending order

overwrites the original array

Question 20

splice()

Answer 20

adds and/or removes array elements

overwrites the original array.

Question 21

toString()

Answer 21

returns a string with array values separated by commas

does not change the original array

Question 22

unshift()

Answer 22

adds an element to the front of an array

Question 23

valueOf()

Answer 23

returns the array itself, does not change the original array