Pick "One"-Liner

pick.js

const pick = (obj, props) => Array.prototype.reduce.call(
  props, 
  (built, prop) => (
    Object.prototype.hasOwnProperty.call(obj, prop) 
      ? Object.assign({}, built, {[prop]: obj[prop]}) 
      : built
  ), {}
)

usage.js

const myObject = {a:'1', b:'2', c:'3', d:'4'}

pick(myObject, ['b','d'])
// Object {b: "2", d: "4"}

pick(myObject, ['a','x'])
// Object {a: "1"}