Omit matching object keys
JavaScript, Object · Oct 21, 2020

Creates an object composed of the properties the given function returns falsy for.
- Use
Object.keys()
andArray.prototype.filter()
to remove the keys for whichfn
returns a truthy value. - Use
Array.prototype.reduce()
to convert the filtered keys back to an object with the corresponding key-value pairs. - The callback function is invoked with two arguments: (value, key).
const omitBy = (obj, fn) => Object.keys(obj) .filter(k => !fn(obj[k], k)) .reduce((acc, key) => ((acc[key] = obj[key]), acc), {}); omitBy({ a: 1, b: '2', c: 3 }, x => typeof x === 'number'); // { b: '2' }