What Is Javascript?

You can’t get very far in tech without running smack into the word javascript. Whether it’s the Facebook timeline automatically updating on your screen or Google suggesting search terms based on the first few letters you type, chances are that was done with javascript. But javascript isn’t as scary as it sounds, and it’s essential to web development.

JS is a programming language that lets you make websites and applications dynamic and interactive. It’s used in conjunction with hypertext markup language (HTML) and cascading style sheets (CSS). The majority of modern websites use javascript. It is also one of the most popular programming languages on earth.

The first thing you need to learn is about variables. Variables are where you store the values that will be changed in your code. These values can be anything, from a simple string to a complex data structure. There are a few rules when it comes to naming variables, but in general you need to put them inside quotes if they’re not a string or a number. You can also have multiple variables referring to the same value. In this case you need to put them in double quotes if they are not the same variable name, or in single quote marks if the same variable is being referenced.

If you want to change a value in your code, then you have to assign the new value to the variable. When you do this, the old value will be overwritten and the new value will become the current value of the variable. The original value remains stored in the memory, but it is no longer accessible or reachable by your code. The garbage collector will scan the memory heap periodically and deallocate any objects or data structures that are no longer being referenced by your code.

Functions are another essential part of javascript. There are two kinds of functions: regular and arrow functions. Arrow functions are introduced in ECMAScript 2015 and shorten the syntax for writing functions. Both regular and arrow functions are evaluated at runtime. Functions are a critical part of any language, and it’s important to understand how they work.

In javascript, you can write code to do nearly anything. This is why it’s so powerful. You can even create entire pages that are dynamically rendered based on user input. There are some limitations though, such as performance. The more javascript you have on your page, the slower it will perform because the browser has to download, parse, and execute all of the code. This is especially true if you use tools like Google Analytics, tag managers, or ad platforms.

There are ways to optimize javascript for better performance, including using the shim library, minimizing the number of calls, and inlining functions. There are many different resources on the web to help you improve your site’s javascript performance. JS is one of the most widely used modern technologies and it’s essential to have a good understanding of how it works.