pick.js

function pick(obj, props) {
  return props.reduce(function(result, prop) {
    result[prop] = obj[prop];
    return result;
  }, {});
}

const person = {
  name: 'Jonathan',
  age: 21,
  gender: 'male'
}

const picked = pick(person, ['name', 'age']);

console.log(picked); // Result { name: 'Jonathan', age: 21 }