JavaScript

Updated Oct 25, 2020 · 5 min read

What is JavaScript?

JavaScript (JS) is a free programming language that sets the dynamic behavior on most websites. The dynamic behavior can mean animated graphics, dropdown menus, validation and error message displays, and interactive maps. Along with HTML and CSS, JavaScript is one of the core technologies used on the web.

Client-side language

JavaScript is used mostly as a client-side scripting language. In other words, developers embed JavaScript in the HTML documents that users interact with. In these cases, developers use JavaScript to interact with the Document Object Model (DOM). The major web browsers all have a JavaScript engine that executes code on client devices.

Features

Scripting language

JavaScript is a scripting language. A scripting language is a programming language that's interpreted rather than compiled. That is, the JavaScript engine translates code into machine code when the code runs rather than before the code runs.

Weakly typed

JavaScript is a weakly typed, rather than a strongly typed, programming language. A weakly typed programming language is a language in which variables aren't bound to a specific type, such as integer, string, or long. Other weakly typed languages include PHP and C.

Object-oriented programming

JavaScript supports the object-oriented programming paradigm. The paradigm lets developers build applications with reusable and easily maintainable blocks of code. It helps developers design code more efficiently.


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