JavaScript Arrays Quiz

Which of the following is the correct way to create an empty array in JavaScript?

• let emptyArray = {};

• let emptyArray = [];

• let emptyArray = new Array();

• Both b) and c)

What is the correct syntax to access the second element of an array named colors?

• colors[1]

• colors.second

• colors(1)

• colors[2]

How do you add an element to the end of an array named fruits?

• fruits.add("grape");

• fruits.push("grape");

• fruits.append("grape");

• fruits.insert("grape");

How do you remove the last element from an array named numbers?

• numbers.remove();

• numbers.pop();

• numbers.delete();

• numbers.shift();

What does the length property of an array return?

• The index of the last element.

• The number of elements in the array.

• The type of the array.

• The first element of the array.

Which of the following is a valid way to create a 2D array in JavaScript?

• let matrix = [1, 2, 3, 4, 5, 6];

• let matrix = [[1, 2, 3], [4, 5, 6]];

• let matrix = { 1: [1, 2, 3], 2: [4, 5, 6] };

• let matrix = new Array(2, 3);

How do you access the element at the second row and first column of a 2D array named matrix?

• matrix[1][0]

• matrix[0][1]

• matrix[2][0]

• matrix[0][2]

What is the purpose of the forEach() method in JavaScript arrays?

• To add an element to the end of the array.

• To remove the first element from the array.

• To iterate over each element in the array.

• To sort the elements in the array.

Which method can be used to join all elements of an array into a string?

• concat()

• join()

• toString()

• Both b) and c)

Which method can be used to reverse the order of elements in an array?

• reverse()

• sort()

• shift()

• unshift()