What is JavaScript?

In the world of web development, you can’t get very far without running smack into javascript. You might not realize it, but javascript powers some of the most important digital tools and services you use – like the Facebook timeline that automatically updates on your screen or the Google search results that suggest keywords as you type.

javascript is a scripting language that adds dynamism to webpages, allowing developers to create interactive experiences for users. You might think of it as the software that underlines a typo in your blog post or makes a popup window appear when you click on a button.

JavaScript is a high-level programming language, which means it doesn’t manage hardware resources such as memory or CPU. The language is compiled into machine code, which is translated to 0s and 1s by a JavaScript engine (which exists in every browser) and executed. The engine also has a garbage collector, which is an algorithm that cleans up old unused objects from memory.

The language supports several data types, including strings and numbers. Strings are sequences of characters, and you can indicate that a value is a string by using single or double quotes around the value. Numbers are represented as int values and don’t require quote marks. You can also compare values with the = and – operators. Other common operations include +, -, *, and / (multiplication and division). In addition, you can use string functions to manipulate text, such as swapping letters and converting between upper and lowercase.

JavaScript uses object-oriented design, where everything is an object with properties and methods. It also has recursion, where you can invoke a function within itself. Functions in javascript can take any number of parameters and return a value of their choosing. They can also declare their own private variables, which are only accessible to the function body.

A function can be declared as static or nonstatic. Static functions are always evaluated, but nonstatic functions are not. A static function cannot be changed, but nonstatic functions can be reassigned to a new value. Nonstatic functions are also called class-scoped.

Variables in javascript are named with either const or let. Const declarations prevent reassignments, but not mutations. Variables declared as let are subject to both reassignments and mutations, but if they’re not assigned a value, they will remain undefined.

The language has important tools that help developers write more readable code. Most popular web browsers have built-in JavaScript debuggers, and there are static program analysis tools such as ESLint or JSLint, which scan a program for conformance to a set of standards and guidelines. Many text editors support syntax highlighting for javascript. You can find tutorials and examples of javascript online. Some of these resources are free, but others, such as Codecademy, offer a complete course for a one-time payment. Ultimately, you’ll be able to find the best platform for your learning style and needs.