Array.prototype.sortBy.js

Array.prototype.sortBy = (function() {
  const sorters = {
    string: (a, b) => a < b ? -1 : (a > b ? 1 : 0),
    number: (a, b) => a - b,
  };
  return function(prop) {
    const type = typeof this[0][prop] || 'string';
    return this.sort((a, b) => sorters[type](a[prop], b[prop]));
  };
})();