Arrays: removing, inserting, and extracting elements

Question 1

What keyword removes the first element of an array?

Answer 1

shift

Question 2

What keyword adds one or more elements to the beginning of an array?

Answer 2

unshift

Question 3

What keyword inserts new elements anywhere in an array and/or removes elements from an array?

Answer 3

splice

Question 4

What keyword copies elements from an array to another array?

Answer 4

slice

Question 5

This statement created the array:
var sizes = ["S", "M", "XL", "XXL", "XXXL"];
Insert "L" into the array between "M" and "XL"

Answer 5

sizes.splice(2, 0, “L”);

Question 6

This statement created the array:
var sizes = ["S", "M", "XL", "XXL", "XXXL"];
Copy the first 3 sizes of the array and put them into a new array, regSizes.

Answer 6

var regSizes = sizes.slice(0, 3);

Question 7

Remove the first element of an array.

Answer 7

airlines.shift();

Question 8

Add three number elements to the beginning of an array.

Answer 8

scores.unshift(0, 13, 5);

Question 9

This statement created the array:
var pets = ["dog", "cat", "ox", "duck", "frog"];
Add 2 elements after "dog" and remove "cat", "ox", and "duck".

Answer 9

pets.splice(1, 3, “fish”, “monkey”);

Question 10

This statement created the array:
var pets = [“dog”, “cat”, “ox”, “duck”, “frog”];
Remove “cat” and “ox”.

Answer 10

pets.splice(1, 2);

Question 11

This statement created the array:
var pets = [“dog”, “cat”, “ox”, “duck”, “frog”, “flea”];
Reduce it to “duck” and “frog” using slice.

Answer 11

pets = pets.slice(3, 5);