The ECMAScript 2015 specification introduced a Map class. A Map instance provides convenient methods around key-value-pairs. Objects in JavaScript are key-value-pairs as well. Yet, you can’t pass an existing object to the map constructor. This tutorial shows you how to create a JavaScript map from an existing object. {{outline} …

In a recent project, we needed to calculate differences between data points. Each data point represented an amount of money. The difference between the two data points should always be a positive number in context with prices going up or down. This tutorial shows you how to always retrieve a …

Sometimes you want to pick a random item from a JavaScript array. For example, when picking a winner from a list of participants. Or when highlighting one of your product’s great features. This tutorial shows you how to grab a random array item in JavaScript. {{outline}} Get a Random …

Occasionally you need to shut down or reboot your Linux servers. The Linux operating system comes with the built-in shutdown command. This command allows you to power off or reboot a computer. This tutorial shows you how to shut down or reboot a Linux machine. {{outline}} Shutdown Your Ubuntu/Debian …

You may encounter the $connection_upgrade variable in your nginx configuration when working with Websockets or using an nginx config generator. The $connection_upgrade variable isn’t available by default. Yet, it’s a recommended practice to define and use it in your reverse proxy settings. This tutorial shows you …

When updating nginx to a newer version, you may run into deprecated configurations. Nginx uses a YAML-like definition format to create configurations. This format evolves over time by adding, removing, or changing keywords. This tutorial shows you how to fix nginx’s “ssl” deprecation warning telling you to use “listen …

Leaving a loop early is a common practice in programming. Stopping or breaking out of an Array#forEach iteration in JavaScript is only possible by throwing an exception. Also, the Mozilla Developer Network states “when you need to stop forEach, it’s the wrong tool.” This tutorial points you to …

UNIX-based operating systems have a touch utility available on the command line. touch updates the access and modification times of a given file to the current time. A nice benefit: touch also creates the given file if it doesn’t exist. This tutorial shows you how to implement a touch-like …