Beginner JavaScript

Question 1

JavaScript runs in your web browser alongside HTML and CSS, and can be added to any web page using a _______ tag.

Answer 1

script

Question 2

What are the three types of JavaScript included in HTML pages?

Answer 2

1. ) Internal
2. ) External
3. ) Inline – Should be avoided

Question 3

What is the file extension used by JavaScript files?

Answer 3

js

Question 4

Storing data so we can use it later is achieved with ______.

Answer 4

Variables

Question 5

var surname = prompt(‘Greetings friend, may I enquire as to your surname?’);

Answer 5

Prompt the user to enter a surname and store the contents of that response in a variable named surname.

Question 6

What are the two parts to a variable?

Answer 6

The variable’s name and value

Question 7

What are the two steps to creating a variable?

Answer 7

declaration and initialization

Question 8

What is the variable declaration?

Answer 8

Declaration is declaring a variable to exist.

Question 9

What keyword is used to declare a variable?

Answer 9

var

Question 10

What is Initialization?

Answer 10

Initialization is giving a variable its value for the first time.

Question 11

What is a string?

Answer 11

A collection of letters. A string is surrounded by single or double quote marks.

Question 12

What is assignment?

Answer 12

It looks very similar to initialization. You use the equals sign, but there’s no need for the var keyword because we’ve already declared the variable.

Question 13

What capitalization convention does this variable name use: piecesOfFruit?

Answer 13

Camel casing

Question 14

Mathematical symbols are called _______.

Answer 14

Operators.

+, -, *, /, %

Question 15

When a comparison is made the outcome is either true or false; a special kind a of data called a _____. This is _____.

Answer 15

boolean and logic

Question 16

What operator should be used to find out when two values are equal?

Answer 16

triple equals operator (“===”)

Question 17

What operator should be used to find out when two values are NOT equal?

Answer 17

triple not equal operator (“!==”)

Question 18

What operators are used to determine which value greater or less than another?

Answer 18

greater than operator (“>”)

less than operator (“

Question 19

What operators can be used to determine greater than or equal to? Less than or equal to?

Answer 19

greater than or equal to (“>=”)

less than or equal to operators (“<=”)

Question 20

______ is used to make decisions in code

Answer 20

Logic created with conditionals

Question 21

What is the most commonly used conditional?

Answer 21

if or if-else

Question 22

How does the if statement work?

Answer 22

if some logic (the condition) is true, run a block of code, else run a different block of code

Question 23

The code between the braces - “{” and “}” - is called a _______.

Answer 23

A block

Question 24

_______ are a way of repeating the same block of code over and over.

Answer 24

Loops

Question 25

What the two most commonly used types of loops?

Answer 25

1. ) for | 2. ) while

Question 26

How do loops work?

Answer 26

They combine a conditional and a block, running the block over and over until the logic of the conditional is no longer true, or until you force them to stop.

Question 27

A ______ repeats a block of code while a condition is true

Answer 27

while loop

Question 28

_______ combines three semicolon-separated pieces information between the parentheses: initialization, condition and a final expression.

Answer 28

for loop

Question 29

________ are reusable blocks of code that carry out a specific task.

Answer 29

Functions

Question 30

To execute the code in a function you _______.

Answer 30

call it or invoking the function

Question 31

A function can be passed _______ to use

Answer 31

arguments

Question 32

A function may _______ a value to whatever called it.

Answer 32

return

Question 33

How to create a function?

Answer 33

1. ) Use the function keyword 2. ) List arguments in parenthesis 3. ) Create a block of code that creates functionality

Question 34

In a function, the _____ keyword also stops execution of the code in the function; nothing after it will be run.

Answer 34

return

Question 35

``` var add = function (a, b) { return a + b; }; ``` What are a and b?

Answer 35

Parameters

Question 36

JavaScript objects consist of what two parts?

Answer 36

properties and methods

Question 37

An object can be stored in a variable, and the properties and methods accessed using _________.

Answer 37

dot syntax

Question 38

What are object properties?

Answer 38

pieces of data

Question 39

What are JavaScript methods?

Answer 39

Functions that are built into objects

Question 40

``` var jedi = { name: "Yoda", age: 899, talk: function () { alert("another... Sky... walk..."); } }; ``` What are name and age?

Answer 40

Properties -- Essentially variables that are built into objects

Question 41

True or False? Properties can be any kind of data including objects and arrays

Answer 41

True

Question 42

What is a nested object?

Answer 42

An object that is a property of another object

Question 43

True or False? You can create an empty object and then add properties and methods to it.

Answer 43

True

Question 44

________ are lists of any kind of data.

Answer 44

Arrays

Question 45

Each item in the array has an ______ — a number — which can be used to retrieve an element from the array.

Answer 45

An index

Question 46

Array indices start at _____

Answer 46

0

Question 47

The last element of an array has an indices of ______

Answer 47

The length of the array minus 1

Question 48

In JavaScript, you create an array using the _____ syntax:

Answer 48

array-literal syntax Example: var shoppingList = ['Milk', 'Bread', 'Beans'];

Question 49

You retrieve a specific element from an array using _____ syntax

Answer 49

square bracket syntax Example: shoppingList[0]; // retrieve a value Example: shoppingList[1] = 'Cookies'; // set a value

Question 50

What is length? shoppingList.length;

Answer 50

The array length property.

Question 51

You can use _____ and ______ methods to add and remove elements from the end of the array

Answer 51

push and pop Example: shoppingList.push('A new car');