JavaScript Midterm Exam

Question 1

JavaScript is used to add ______ to web pages.

Answer 1

behavior

Question 2

True or False?

Browsers begin executing JavaScript only when the entire page has loaded.

Answer 2

False

Question 3

Add JavaScript to your page with the _____ element.

Answer 3

script

Question 4

Use the _____ attribute in a tag to link to a separate JavaScript file.

Answer 4

src

Question 5

JavaScript programs are made up of a series of ______.

Answer 5

algorithms

Question 6

You can put your JavaScript in two places, ______ in the web page, or you can _____ to a separate file containing your JavaScript from your HTML.

Answer 6

right, link

Question 7

One of the most common JavaScript statements is a variable declaration, which uses the _____ keyword to declare a new variable and the assignment operator, ____, to assign a value to it.

Answer 7

var, =

Question 8

True or False?

JavaScript expressions compute values.

Answer 8

True

Question 9

Three common types of expressions are ____, ______, and _____ expressions.

Answer 9

numeric, string, boolean

Question 10

______ allow you to make decisions in your code.

Answer 10

if/else

Question 11

____/____ statements allow you to execute code many times by looping.

Answer 11

while/for

Question 12

Use ______ instead of alert to display messages to the Console.

Answer 12

console.log

Question 13

True or False?

Console messages should be used primarily for sending messages to the users.

Answer 13

False

Question 14

______ is the function provided for getting input from a user. If a user hits cancel instead of inputting data, _____ is returned from the function.

Answer 14

prompt, null

Question 15

Code that continuously repeats itself without ever ending is called a(n) _______.

Answer 15

infinite loop

Question 16

What is the ‘And’ Boolean operator in JavaScript symbolized by?

Answer 16

&&

Question 17

______ is the function used in JavaScript for generating random numbers.

Answer 17

math.random

Question 18

______ is the function that always rounds numbers down.

Answer 18

math.floor

Question 19

Boolean operators always result in the values ____ or ______.

Answer 19

true, false

Question 20

To get a false value from an OR operator (||) both values must be ______.

Answer 20

false

Question 21

_______ is an English approximation of what your code should do.

Answer 21

psuedocode

Question 22

What happens if you pass too many arguments to a function in JavaScript?

Answer 22

It ignores the extra arguments and runs perfectly fine.

Question 23

True or False?

In JavaScript, the return type needs to be declared in the function signature.

Answer 23

False

Question 24

A variable declared outside of a function is called a _______ variable.

Answer 24

global

Question 25

A variable declared inside of a function is called a ______ variable.

Answer 25

local

Question 26

The area of code in which you can use a variable is called the variable’s ______.

Answer 26

scope

Question 27

If you forget to declare a variable inside of a function, its scope will be ______.

Answer 27

global

Question 28

True or False?

JavaScript requires a function to be defined prior to the point of calling it in the code.

Answer 28

False

Question 29

What method allows you to add a value to the end of an array?

Answer 29

.push();

Question 30

An array item that has not been initialized will have the value: _______.

Answer 30

undefined

Question 31

True or False?

In JavaScript, arrays may grow beyond their initialized size.

Answer 31

True

Question 32

You identify an element in an array using its ______.

Answer 32

index

Question 33

Which property of an array will tell you the number of items in the array?

Answer 33

.length

Question 34

A ______ array occurs when there are undefined terms in the middle of an array.

Answer 34

sparse

Question 35

______ is the process of organizing your code so that it is easier to read and maintain.

Answer 35

refactoring

Question 36

_______ is looping through each item in an array to process each item.

Answer 36

iterating

Question 37

The index of the first item in an array is _____.

Answer 37

0

Question 38

The last index of an array is always one ____ than the length of the array.

Answer 38

less

Question 39

JavaScript objects are a collection of _______ and _______.

Answer 39

Properties, Behaviors

Question 40

When declaring an object, each property of an object has a name followed by a _____ then a value.

Answer 40

colon

Question 41

When declaring an object, properties are separated from each other by a ______.

Answer 41

comma

Question 42

To access a property of an object you use _______ notation.

Answer 42

dot

Question 43

You can remove a property from an object using the _____ operator.

Answer 43

delete

Question 44

Variables for objects hold a _______ to the object.

Answer 44

reference

Question 45

_______ is a keyword that always refers to the object whose method is being called.

Answer 45

this

Question 46

True or False?

A method is a function that has been assigned to a property name in an object.

Answer 46

True

Question 47

You can iterate through an object’s properties using a _______.

Answer 47

for each

Question 48

Object references are passed by _______, just like primitive variables.

Answer 48

values

Question 49

DOM stands for __________.

Answer 49

Document Object Model

Question 50

To find and access an element on a web page using its ID, use the _______ method of the _______ object.

Answer 50

getElementByID, document

Question 51

To access or change the contents of an element you can alter its _________ property.

Answer 51

innerHTML

Question 52

True or False?

ID’s on a web page must be unique.

Answer 52

True

Question 53

True or False?

Classes on a web page must be unique.

Answer 53

False

Question 54

______._______ is the object and property that will call a function only after the web page is fully loaded.

Answer 54

window.onload

Question 55

Giving a function to an object that knows about an event so that it runs the code when the event happens is known as a _________ function or an event handler.

Answer 55

callback

Question 56

To get the value of an attribute of an HTML element, use the ________ method.

Answer 56

getAttribute

Question 57

To change an attribute of an HTML element, use the ________ method.

Answer 57

setAttribute

Question 58

Anytime you call method to locate an element or attribute that does not exist, ______ is returned.

Answer 58

null

Question 59

True or False?

The web browser creates the DOM for the web page.

Answer 59

True

Question 60

True or False?

The innerHTML property holds only the text content of an element.

Answer 60

False