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 are useful for input such as authorization or for a search engine. Variables can also be undefined or null.

Functions

Functions are keywords used in object-oriented programming. These are used to run code multiple times, for example, a login button. They can set up 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 are triggers 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 on 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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