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 …

Apr 3, 2018 · What does the <T> mean? That is TypeScript's Generics declaration. Excerpt: A major part of software engineering is building components that not only have well-defined and …

What does the ampersand (&) mean in a TypeScript type definition? Asked 9 years, 4 months ago Modified 1 year ago Viewed 97k times

Apr 21, 2019 · The as keyword is a type assertion in TypeScript which tells the compiler to consider the object as another type than the type the compiler infers the object to be.

export function foo(arg: string): arg is MyType { return ... } I haven't been able to search for is in either the docs or google, it's a pretty common word and shows up on basically every page. …

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 …

The key aspect to interfaces in typescript that distinguish them from types is that they can be extended with new functionality after they've already been declared.

Feb 2, 2019 · Alternatively, you can type name1 as string | undefined, and handle cases of undefined further down. However, it's typically better to handle unexpected errors earlier on. …

Jul 20, 2018 · 880 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 …