Array Methods

Question 1

Array.from()

Answer 1

creates a new, shallow-copied Array instance from an array-like or iterable object.
> Array.from((string,array),(map func))

Question 2

Array.of()

Answer 2

creates a new Array instance from a variable number of arguments, regardless of number or type of the arguments.
> Array.of(7) // [7]
> Array.of(1,2,3) // [1, 2, 3]

Question 3

Array()

Answer 3

array constructor, if passed in an integer, creates that many empty spots for the integer, or if a list of integers, creates that array
> Array(7) // creates an array with 7 empty spots of that length
> Array(1, 2, 3) // [1, 2, 3]

Question 4

.concat()

Answer 4

Merges two arrays together, doesn’t change the existing arrays, returns new array
> array1 = [ 1, 2, 3], array2 = [4, 5, 6]
> array1.concat(array2) // [1, 2, 3, 4, 5, 6]

Question 5

.every()

Answer 5

tests whether all elements in the array pass the test implemented by the provided function. It returns a Boolean value.
> .every((function_to_test)) // True or false

Question 6

.fill()

Answer 6

changes all elements in an array to a static value

.fill((value),(start),(end))

Question 7

.filter()

Answer 7

creates a new array based on if the elements pass the given function

Question 8

.find()

Answer 8

returns the value of the first element in the provided array that satisfies the provided testing function.

Question 9

.findIndex()

Answer 9

returns the index of the first element in the array that satisfies the provided testing function. Otherwise, it returns -1.

Question 10

.includes()

Answer 10

determines whether an array includes a certain value among its entries, returning true or false as appropriate.

Question 11

.pop()

Answer 11

removes the last element from an array and returns that element. This method changes the length of the array.

Question 12

.reverse()

Answer 12

reverses an array in place. The first array element becomes the last, and the last array element becomes the first.

Question 13

.shift()

Answer 13

removes the first element from an array and returns that removed element. This method changes the length of the array.

Question 14

.some()

Answer 14

tests whether at least one element in the array passes the test implemented by the provided function. It returns a Boolean value.
> array.some((func)) // true or false

Question 15

.unshift()

Answer 15

adds one or more elements to the beginning of an array and returns the new length of the array.
> array.unshift((element1),(element2)…)