Comp Sci Test 10/7

What is JavaScript

The worlds most popular programming language

When was JavaScript established

1995

How many websites use JavaScript

98% of all websites use JavaScript on the client side for web page behavior

JavaScript past names

Initially called mocha and then renamed to live script

What is JavaScript used for

used to create interactive elements on websites

What does JavaScript run in

Runs Directly in the browser and can make websites dynamic

What is used along side HTML and CSS

JS is used alongside HTML and CSS to build modern web applications

What are variables used for

Used to store data and allow you to give a name to your data so you can refer to it later

1_let

For variables that can be reassigned later

const

For variables that cannot be reassigned after they’re set

var

An older way to declare variables, not commonly used now due to scope issues

String

Text/characters

Number

Integers and decimals

BigInt

Very large integers

Boolean

True or false

Undefined

A variable with no assigned value

Null

Intentional absence of a value

Symbol

Creates a unique identifier

Object

Collection of related data

number example

let number = 10;

strings example

let text = “Hello”;

Booleans example

let is True = true;

Arrays example

let fruits = [“apple”, “banana”, “cherry”];

Objects example

let person = {name: “John”, age: 25},

Conditionals

if-else statements are used to perform different actions based on conditions

Function

A block of code designed to perform a task

Loops

help repeat tasks easily

DOM Manipulation

Allows JavaScript to interact with and change HTML elements

What does DOM stand for

Document Object Model

Function to call to print to the screen

println

function used to ask the user to enter text

readLine

To ask the user of the program for a number, which function should you use

readInt and readFloat