Like any other language, JavaScript comes with a set of useful functions. All together they make up the so-called standard library. It usually contains thousands of functions you can't remember, and you don't have to. It is assumed that any programmer knows where to look for their documentation and has a rough idea of what they want to achieve. And the rest is a matter of technique. Without the Internet, most programmers wouldn't be able to program anything.
To newcomers, it often looks like this: "Go I know not whither and fetch I know not what". In other words, most people have no idea how to learn about these functions when they don't know anything at all. Oddly enough, there is no way to know everything you need to know once and for all. As you grow as a developer, you learn all the exciting features that solve your problems more elegantly, thus expanding your toolbox.
Here are some tips to learn about new features:
- Always keep track of what you are working with (the data type) at the moment. You will most likely find the function you need in the appropriate chapter of the documentation. For example, you need to study string functions to work with strings
- From time to time, open the standard functions section of the topic you are studying and just run through them, learning the signatures and ways to use them
- Read other people's code more often, especially code from the libraries you're using. It's all available on GitHub
The JavaScript standard library's structure has its peculiarities. Since the code can run in different environments, such as a server or a browser, the capabilities of the standard library are highly dependent on the use case. For example, you can't perform some server tasks in a browser. For server-side documentation, see https://nodejs.org. The server portions of the standard library are organized into modules, each module has its own page with full descriptions of all its functions. In particular, the module fs is required to work with the file system, its functions allow you to write and read files.
As for the browsers, there's not much stuff. For the most part, it's some basic functions built into the language. For example, the math functions we've seen before.. The rest of the features you can add via third-party libraries.
