In some situations, you need to detect the operating system running the Node.js process. You can do that by using Node.js’ built-in os module. {{outline}} Check if the Operating System is Linux The os module in Node.js provides a platform method. This platform method allows you to …

In some situations, you may need to retrieve the extension of a file on your local disk. Node.js comes with built-in functionality that you can use in your application. This tutorial shows you how to retrieve the file extension in Node.js. {{outline}} Retrieve the File Extension Node.js’ …

Node.js ships with the native fs module to interact with the local file system. The fs module supports retrieving statistics for a file on your local disk. You may also get the size of a file from these statistics. This tutorial shows you how to retrieve the file size …

You can download a file in Node.js in different ways. Node.js comes with built-in functions to download and save a file to your local disk. You can combine the integrated https and fs modules to download files from the Internet. This tutorial shows you how to use native …

The JavaScript stdlib is missing a method to detect whether a given input is a string value in lowercase format. Yet, we can build our own isLowerCase method using the existing methods. This tutorial shows you how to create a method detecting whether an input is in lowercase. {{outline}} Determine …

JavaScript is missing a method to detect whether a given input is a string value in uppercase format. What’s existing are methods allowing us to create our own isUpperCase utility method. This tutorial shows you how to create a method detecting whether an input is in uppercase. {{outline}} Determine …

JavaScript contains the global Symbol object allowing you to create unique symbol values. You may use symbols to add a property to an object that doesn’t collide with other keys because symbols are hidden from the usual access patterns. This tutorial shows you how to detect whether a given …

A JavaScript object contains key-value pairs. Depending on your use case you may need to iterate through all these key-value pairs. JavaScript offers different types of loops to iterate through the object. The allrounder is the for…in loop. Since ECMAScript 2015 you can use Object.keys. Starting from ECMAScript …