What is JavaScript?

As a developer, you know that your web pages require HTML (hypertext markup language) and CSS to display text and graphics. But if you want to add real functionality and interaction to your site, javascript is where it’s at.

JavaScript is a computer programming language that makes websites and web applications dynamic, interactive, and accessible. It’s the third element in the web development trinity: HTML provides structure and CSS adds a beautiful aesthetic, but JS is what brings everything to life.

Developed in 1995 by Brendan Eich of Netscape, JavaScript was designed to give Web browsers the ability to interact with users and make static pages more dynamic. It is a dynamically typed scripting language that uses object-oriented programming principles. It also has procedural elements, such as loops and functions.

JavaScript has an extremely large library of functions, and it’s one of the most commonly used languages on the Internet. It’s a general purpose, cross-platform, and interpreted compiled programming language, which means that it can be executed in a number of different environments, including desktop and mobile devices.

While the syntax of js may be daunting to new developers, there are many online resources to help them get started. CodePen, for example, is a great place to practice coding in JavaScript. Many professional coding schools also offer courses in javascript for students looking to start their careers in the field.

The most basic element of any javascript program is the variable, which represents a value of any data type. It is important to understand the concept of variables in JavaScript because they are the building block of any application. Without them, you wouldn’t be able to change the content of your page by simply changing the contents of a variable.

A var can store anything from a string to an integer or even a function. When JavaScript executes your code, it reads the line of code and then allocates memory to the corresponding variable or function. If the code doesn’t have a variable named name, it will assign undefined to that variable.

Once the memory is allocated, JavaScript starts running through the code line by line. As it does, it evaluates the variable or function. If the evaluation is successful, it will assign a value to the variable or function and continue executing. If not, it will return an error message. This process is called just-in-time compilation, and it’s what makes JavaScript fast. In comparison, other dynamic languages use ahead-of-time compilation and can be much slower.