What Is Javascript?

You won’t get far in the tech world without running into javascript. It’s the programming language that powers web features like drop-down menus, form validation, and real-time data display. It’s also used to create the backbone of web animation and make websites dynamic. It’s even used to animate the Facebook timeline and suggest search terms based on the letters you type into Google.

But that’s only scratching the surface of what javascript can do. The language has a lot of quirks, and learning to code in it takes time. The syntax can be confusing, and there are many rules and idioms to remember. But it’s worth the effort to understand javascript because it’s an essential part of modern front-end development.

The first thing to understand about javascript is that it’s an interpreted language, which means the code is run in the browser and interpreted on the fly. This is different from compiled languages, which are compiled into a binary file that is then executed by the computer. But despite the fact that it’s interpreted, javascript is still very fast and can easily outperform compiled languages. It has the added benefit of being created for the web, so it’s been optimized to work in a browser environment. Three of the biggest software companies in the world—Microsoft, Apple, and Google—all produce high-performance javascript interpreters for their browsers.

Every javascript program has one global execution context (GEC). This is where top-level code will execute, and where functions will be executed once they’re called. A function will start out at the bottom of the call stack and be moved up by each invocation, as it is called. The GEC and all the stack frames it contains are what is known as a LIFO data structure, meaning that earlier jobs are executed before later ones.

When you create a variable in javascript, it’s important to name it correctly. You can use any value as a variable name, but it’s important to keep in mind that values are objects in javascript. A variable can hold any kind of object, and you can access that object’s properties by using the dot operator. For example, you can find the length of a string variable by calling its len(string) property. Variable names must also comply with naming rules, such as being enclosed in single or double quotes and not starting with an underscore. Finally, there are some specialized values, such as int and boolean, that don’t require quote marks.

Finally, it’s important to note that javascript is case sensitive. If you’re writing a script, you need to be careful that your variables are named the same way in all places in the code.

Another feature of javascript is that it allows you to use the throw statement to catch errors in your code. This includes any error from the built-in operations, as well as your own functions. In addition to throwing an error, you can use the instanceof operator to determine what kind of error it is.