函数 objectMap

objectMap<K extends string, V, NK extends string | number | symbol = K, NV = V>(
obj: Record<K, V>,
fn: (key: K, value: V) => undefined | [NK, NV],
): Record<NK, NV>

Map key/value pairs for an object, and construct a new one

objectMap({ a: 1, b: 2 }, (k, v) => [k.toString().toUpperCase(), v.toString()])
// { A: '1', B: '2' }

Swap key/value:

objectMap({ a: 1, b: 2 }, (k, v) => [v, k])
// { 1: 'a', 2: 'b' }

Filter keys:

objectMap({ a: 1, b: 2 }, (k, v) => k === 'a' ? undefined : [k, v])
// { b: 2 }