TypeScript's relation to JavaScript. TypeScript is a typed superset of JavaScript that compiles to plain JavaScript - typescriptlang.org. JavaScript is a programming language that is developed by ECMA's Technical Committee 39, which is a group of …

While the ?? operator isn't available in current LTS versions of Node (v10 and v12), you can use it with some versions of TypeScript or Node: The ?? operator was added to TypeScript 3.7 back in November 2019. And more recently, the ?? operator was included in ES2020, which is supported by Node 14 (released in April 2020).

Oct 21, 2024 · I'm working on a project using Vite, and I want to understand the difference between using TypeScript alone and TypeScript with SWC. I've searched online but couldn't find a clear explanation. I believe it would be helpful to get answers from experienced developers, which is why I'm asking here.

An object in JavaScript is a key/value map, and an "object type" is typescript's way of typing those key/value maps. Both interface and type can be used when providing types for an object as the original question makes clear. So when do you use type …

JavaScript freely converts between these types. When you access a method like charAt on a string primitive, JavaScript wraps it in a String object, calls the method, and then throws the object away. TypeScript models this distinction by having distinct types for the primitives and their object wrappers: string and String; number and Number

Dec 13, 2021 · This first statement from the docs should be self explanatory for the first two statements in your code: The nullish coalescing operator (??) is a logical operator that returns its right-hand side operand when its left-hand side operand is null or undefined, and otherwise returns its left-hand side operand.

Javascript's nice face (one of the benefits) is built-in support for duck typing. "If it walks like a duck and it quacks like a duck, then it must be a duck." So, in Javascript, if two different objects have one similar method (e.g. render()) they can be passed to a function which expects it:

Jul 30, 2018 · A TypeScript/JavaScript class is a function. A TypeScript type is just a definition that helps the TS compiler check the code. It is not translated to anything in the generated JS code.

Jul 20, 2018 · TypeScript 3.0 introduces unknown type, according to their wiki: unknown is now a reserved type name, as it is now a built-in type. Depending on your intended use of unknown, you may want to remove the declaration entirely (favoring the newly introduced unknown type), or rename it to something else.

What is the current standard in 2017 in Javascript with for() loops vs a .forEach. I am currently working my way through Colt Steeles "Web Dev Bootcamp" on Udemy and he favours forEach over for in his teachings.