JavaScript

All JavaScript arrays have a built-in function .filter that allows you to filter certain elements and return a new array. To filter a JavaScript array, you need to write a function that will determine the filtering rule....

JavaScript join function is built in to every JS Array. It’s very useful to join the elements of the JavaScript array and convert it into a string. Here’s the basic syntax:...

JavaScript provides a very handy possibility to destructure any array and give custom names to the variables in it. Let’s assume we start with a simple array of numbers: const numbers = [1, 2, 3, 4, 5]; To get the first 2 elements from this array, we can use the destructuring assignment....

So you have a bunch of Promises, and you want to proceed only when all of them are resolved. In JavaScript there are 2 main approaches to solving this. ...

What is TypeScript? TypeScript is a programming language developed and maintained by Microsoft. It introduces additional features like strict type binding (variables are bound to specific data types) to JavaScript and can also be compiled down to JavaScript as well....

What is Intl.Collator and how does it work in JS? What’s the difference between two sorts? What will be logged to the console? . . . . . . ....

Will the length of the JS array change? What’s the output? . . . . . . . . . . . . . . . . . All JavaScript arrays have the push function....

How many errors are in this code snippet? What’s the output? . . . . . . . . . . . . . . . . . In JavaScript there are two ways to get access to the object properties....

What is Object.setPrototypeOf in JavaScript? How does it work? What’s the output? . . . . . . . . . . . . . . . . . Theory The function Object....

What’s the value of the length field for JavaScript functions? What will be logged to the console? . . . . . . . . . . . . ....