4. Adding Interactivity with JavaScript

Question 1

Powerful programming language that provides significant value in web development

add interactivity to websites

Answer 1

JavaScript

Question 2

Server-side JavaScript development

Answer 2

Node.js

Question 3

Scripts run directly within your users’ browsers

Answer 3

Client-side interactivity

Question 4

Responsive and interactive user

Answer 4

interfaces

Question 5

Broad API and third-party service integration that permit

Answer 5

multi-tier applications

Question 6

Development through frameworks like React Native and Iconic

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Cross-platform mobile app development

Question 7

Vast ecosystem of libraries, frameworks and tools

Answer 7

Near-universal browser support

Question 8

JavaScript can be included in your web pages by referencing an external .js file as an attribute of the

Answer 8

<script>
tag
</script>

Question 9

You can drop your JavaScript code between the

 tags in the

Answer 9

Header section of your HTML

Question 10

Since the adoption of “___________” you no longer need to add the text/javascript as an attribute of the

 tag.

Answer 10

HTML5

Question 11

JavaScript is the default scripting language for

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HTML

Question 12

Comments accomplished by

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//

Question 13

Character concatenates all values in sentence

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+

Question 14

To get to command line

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F12

right click browser and select INSPECT

Question 15

Representation of the page code

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Elements tab

Question 16

Live JavaScript environment

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Console

Question 17

Built-in JavaScript function that allows you to output messages or values to the console.

Answer 17

console.log()

Question 18

Primary tool for storing and processing data and is a location in memory that’s identified in your code by a name - more descriptive the better

Answer 18

variable

Question 19

Similar to a variable in that it’s also a named storage location but it represents a value that can’t be reassigned or changed once it is assigned.

ie - lastname

Answer 19

constant

Question 20

data meant to be read literally and not treated as say numbers

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string

Question 21

value of either true or false

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boolean

Question 22

Another way of saying that some variables can be valid more widely than others.

Answer 22

Block Scope

Question 23

Variable values can be accessed from any place and at any level of a program

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global

Question 24

Variable values are available only within a limited block of code

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local

Question 25

A method for hanging the execution of specific code on the status of a condition.

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If block

Question 26

Ordered collection of multiple values listed within square brackets best for ordered lists of elements

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arrays

Question 27

unordered collection of key-value pairs where each key is a string or symbol and each value can be of any type appropriate for representing structured dta with named properties and behaviors.

Answer 27

objects

Question 28

Special value in JavaScript that represents the absence of value assigned to values that have been declared but have not been assigned a value or to function params that have not been provided with arguments.

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undefined

Question 29

Special value in JavaScript that represents the intentional absence of any object value assigned explicitly to indicate the absence of an object or the intentional clearing of an object reference.

Answer 29

null

Question 30

Represents a value that is not a valid number and is returned when a mathematical operation or function expects a numerical result but fails to produce one.

Answer 30

NaN "Not-a-Number"

Question 31

The process of converting a value from one datataype to another.

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Type Conversion Type Coercion

Question 32

JavaScript variables can hold values of different data types and JavaScript automatically performs this when necessary

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Dynamically Typed

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Occurs implicitly (not directly expressed) automatically converts from one type to another based on

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context

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Operator used to increase the value of a variable by 1 and can be placed before or after the variable to influence behavior

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++

Question 35

When ++ is placed before the variable is incremented and its ++x

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NEW value is returned

Question 36

When placed after the variable (X++) the variable is incremented but its

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ORIGINAL value is returned.

Question 37

Operator used to decrease the value of a variable by 1

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decrement (--)

Question 38

when placed after like in x-- the variable is decremented but its

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ORIGINAL value is returned

Question 39

A short way of writing x = x + y

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+=

Question 40

subtraction assignment operator

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-=

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multiplication

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*=

Question 42

Fantastic way to get time consuming, boring, and repetitive work done fast.

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JavaScript Control Structures

Question 43

In a switch this statement is used after each case to exit the switch statement once a match is found

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break

Question 44

loop skips the rest of the body for the next iteration and proceeds to the next

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while loop

Question 45

operator that performs type coercion that tries to convert the operands to a common type before making the comparison.

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==

Question 46

Operator that performs strict equality comparison without any type of coercion and if the types are different, the comparisons immediately return as false.

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===

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inequality

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!=

Question 48

strict inequality

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!==

Question 49

Checks coercion if it is not equal if of different values they are coerced

Answer 49

!=

Question 50

boolean value false number zero empty string the absence of any value (or, null) undefined variables NaN

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javascript falsy

Question 51

any other types of values that are not javascript falsy

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truty

Question 52

represents the structure and content of an HTML document as a tree-like structure where each element, attribute and text node in the HTML document is represented as a node in the DOM tree and provides a way to interact with and manipulate the elements of HTML document using JavaScript

Answer 52

DOM Document Object Model

Question 53

The ability to access, modify and add elements dynamically, change styles and classess, handle events and perform other operations on

Answer 53

documents

Question 54

Top-level object representing the HTML document. that serves as the entry point for accessing the DOM tree and provides methods for navigating and manipulating the document.

Answer 54

Document

Question 55

Represents an HTML element in the DOM tree and has properties that allow you to access and modify attributes, styles and content

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Element

Question 56

common select methods

Answer 56

getElementById getElementByTagName getElementsByClassName

Question 57

base class for all types of nodes in the DOM tree and can be elements, text nodes, comment nodes - etc. They have properties and methods for common operations, such as accessing parent and child nodes, manipulating node content and more.

Answer 57

Node

Question 58

Attached to modes to respond to events like clicks, keypresses, mouse movements

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Event Listeners

Question 59

You can interact with the HTML DOM to dynamically modify the content and behavior of an HTML page.

Answer 59

Using JavaScript

Question 60

method to select elements by their id attribute and it modifies the element's contents and properties using dom manipulation

Answer 60

getElementById

Question 61

Dom manipulation that sets the HTML content inside the selected element. In this case, we change the heading's text to New Heading

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innerHTML

Question 62

Dom manipulates accessing the CSS styles of the selected element that set the paragraph's text color to red.

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Style

Question 63

Dom manipulation that sets the text conent of the selected element that we update the paragrah's text to "This is an updated paragraph"

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textContent

Question 64

displays an alert box with the message button clicked

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showMessage

Question 65

Changes the background color of the

element with the id of myDiv to red when button is clicked

Answer 65

changeColor