Tricks I wish I knew when I learned TypeScript

Re:Tricks I wish I knew when I learned TypeScript by pietrovismara on Tuesday October 12, 2021 @08:23AM (#28838816)

You still can extend types with type intersections:

type A = { id: number }

type B = A & { name: string }

const b: B = { id: 0, name: 'foo' }

[ Parent | on HN ]

Re:Tricks I wish I knew when I learned TypeScript by moron4hire on Tuesday October 12, 2021 @09:58AM (#28839720)

That's creating a new type B. In contrast, interfaces can have their definition spread across multiple code units.

    interface X {
        x(): void;
    }

    interface X {
        y(): void;
    }

    class Y implements X {
        x(): void {
            console.log("hello");
        }

        y(): void {
            console.log("world");
        }
    }

    const z = new Y();
    z.x();
    z.y();

This is important for keeping up with API changes in browsers that may happen faster than the DefinitelyTyped project can keep up.

[ Parent | on HN ]