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 …

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 …

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

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, …

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.

Oct 30, 2012 · I have defined function with typescript without defining a type. You can define a function with callback type parameter like below. You can define multiple return values in the …

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]; …

Apr 7, 2016 · Is key-value pair available in TypeScript? If so, how do I do that? Can anyone provide sample, example, or links?