JavaScript Basics

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JavaScript Basics

Variables

Variables are data stored as a value in a named space. Variables can be used as a mathematical constant, to use in math commands to generate a user output, such as e, which has a value of 2.718281828459045. To declare a new constant, type the keyword "const", and add the assignment declaration. Add the value to declare the constant. Note that constants cannot be changed afterward, which should be self-explanatory. Normal variables work the same way, and can be changed accordingly depending on user input. Variables can also hold strings, which is useful for input such as authorization or for a search engine. Variables can also identify as undefined or null.

Functions

Functions are a keyword used in object-oriented programming. These are used to run code multiple times, for example, a login button. They can setup the procedure and insert it inside of a function named loginProcedure. Using the Document Object Model, they can have the function execute when an HTML element is clicked.

Event Keywords

Events is a trigger usually initiated by user input, which allows certain blocks of code to execute. Here's a complete list.

WebSockets and User Connections

User connections include social networking, messaging between users, or playing an online game. WebSocket is a protocol used for seamless and fast communication listening on a port. Encoded messages are sent over this line, usually in a JSON format. WebSocket is supported by Google Chrome, Firefox, Safari, Microsoft Edge, Internet Explorer, and Opera. This server can be utilized with a variable. Declare a variable and set the value to "new WebSocket()". Inside of the parentheses put the URL (Uniform Resource Locator) of your WebSocket connection. Create custom functions for this to create a chat application or another idea.

Recap

View the references for more info on this topic. Event keywords, WebSockets, Functions, and Variables were all listed in this page.

// Variables
var variable = 1;
const constant = 2;
// Better to use let keyword
let username = user;

// Functions
function myFunction() {
    console.log("Hello World!")
}
// Execute this function
myFunction()

// WebSockets
let socket = new WebSocket("server-url")
/* Add your custom WebSocket
functionality here! */

View the references for more info.

References

This article "JavaScript Basics" is from Wikipedia. The list of its authors can be seen in its historical and/or the page Edithistory:JavaScript Basics. Articles copied from Draft Namespace on Wikipedia could be seen on the Draft Namespace of Wikipedia and not main one.

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