typescript object key type
var stuff: { [key: string]: string; } = {};
stuff['a'] = ''; // ok
stuff['a'] = 4; // error
// ... or, if you're using this a lot and don't want to type so much ...
interface StringMap { [key: string]: string; }
var stuff2: StringMap = { };
// same as above
4
2
// For every properties K of type T, transform it to U
function mapObject<K extends string, T, U>(obj: Record<K, T>, f: (x: T) => U): Record<K, U>
const names = { foo: "hello", bar: "world", baz: "bye" };
const lengths = mapObject(names, s => s.length); // { foo: number, bar: number, baz: number }
Thank you!
2
0
Are there any code examples left?
New code examples in category TypeScript