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 …

Feb 16, 2017 · In TypeScript, what is the ! (exclamation mark / bang) operator when dereferencing a member? Asked 8 years, 9 months ago Modified 6 months ago Viewed 653k …

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. …

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

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.

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.

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 …

Feb 22, 2016 · 10 Type guards in typescript To determine the type of a variable after a conditional statement you can use type guards. A type guard in typescript is the following: An expression …

the operation a! produces a value of the type of a with null and undefined excluded Optional chaining finally made it to typescript (3.7) 🎉 The optional chaining operator ?. permits reading …