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?

Typescript needs to know that the function into which you pass an object is functioning like a type guard. If it just returns type true or false, how can Typescript know that it's indeed a type guard …

Feb 16, 2017 · In TypeScript, what is the ! (exclamation mark / bang) operator when dereferencing a member? Asked 8 years, 8 months ago Modified 5 months ago Viewed 652k …

Apr 25, 2016 · Fixed size array would look like const arr = new Array<number>(3);, though technically it will not be fixed ofc The "fixed length arrays" are an entirely different feature. So, …

Jul 26, 2018 · TypeScript can infer types from values, but you can't generate values from types. const fruit = ["apple", "banana", "grape"] as const; export type Fruit = (typeof fruit)[number]; …

Jan 20, 2013 · Learn how to perform type checks on interfaces in TypeScript and ensure compatibility between objects and their expected types.

Mar 24, 2018 · TypeScript has three confusing types: {}, Object, and object. You can't assign undefined nor null to any of those types except if the strictNullChecks compiler option is disabled.

Nov 5, 2015 · Since the release of deno, you can now execute deno run path/to/file.ts and it will run typescript files in a single command without compiling it to a separate JS file.