Jul 20, 2019 · In JavaScript, it's commonly seen as best practice to use === instead of ==, for obvious and well-known reasons. In TypeScript, which is one to be preferred? Is there even …

Jan 17, 2017 · Yes. As of TypeScript 3.7 (released on November 5, 2019), this feature is supported and is called Optional Chaining: At its core, optional chaining lets us write code …

What is the TypeScript language? What can it do that JavaScript or available libraries cannot do, that would give me reason to consider it?

Feb 16, 2017 · It tells TypeScript to leave the expressions result as it is and pass it to JavaScript. It allows the use of JavaScript semantics in TypeScript, such as using loose equality (with the …

So by using the type guard, typescript now knows whether the is a or , so the corresponding APIs can be called without any design time linting errors. If it is "Super Critical" for that API to be …

When creating or maintaining TypeScript definitions for pure JavaScript modules, interfaces should probably be used for everything that is a class in the original module; particularly …

Yes, your example of defining an interface only for the particular items would be a more useful way to do it. It would be quite rare to have an array of items, but not want to conveniently …

Jul 26, 2018 · You can't get the results of the TypeScript type query operator at runtime, because the type system is erased at runtime. You need to give up on the typeof operator. What you …

Nov 5, 2015 · None of the other answers discuss how to run a TypeScript script that uses modules, and especially modern ES Modules. First off, ts-node doesn't work in that scenario, …

Learn how to dynamically assign properties to an object in TypeScript with this helpful guide.