Sort objects in array

sortBy.js

// SORTS ELEMENTS OF AN ARRAY
// http://jsbin.com/rutumeh/edit?js,console


var sortBy = (function () {
  
  var _toString = Object.prototype.toString,
      //the default parser function
      _parser = function (x) { return x; },
      //gets the item to be sorted
      _getItem = function (x) {
        return this.parser((x !== null && typeof x === "object" && x[this.prop]) || x);
      };
  
  /* PROTOTYPE VERSION */
  // Creates the sort method in the Array prototype
  Object.defineProperty(Array.prototype, "sortBy", {
    configurable: false,
    enumerable: false,
    // @o.prop: property name (if it is an Array of objects)
    // @o.desc: determines whether the sort is descending
    // @o.parser: function to parse the items to expected type
    value: function (o) {
      if (_toString.call(o) !== "[object Object]")
        o = {};
      if (typeof o.parser !== "function")
        o.parser = _parser;
      o.desc = !!o.desc ? -1 : 1;
      return this.sort(function (a, b) {
        a = _getItem.call(o, a);
        b = _getItem.call(o, b);
        return o.desc * (a < b ? -1 : +(a > b));
        //return ((a > b) - (b > a)) * o.desc;
      });
    }
  });
  
  /* FUNCTION VERSION */
  // Sorts the elements of an array
  // @array: the Array
  // @o.prop: property name (if it is an Array of objects)
  // @o.desc: determines whether the sort is descending
  // @o.parser: function to parse the items to expected type
  return function (array, o) {
    if (!(array instanceof Array) || !array.length)
      return [];
    if (_toString.call(o) !== "[object Object]")
      o = {};
    if (typeof o.parser !== "function")
      o.parser = _parser;
    o.desc = !!o.desc ? -1 : 1;
    return array.sort(function (a, b) {
      a = _getItem.call(o, a);
      b = _getItem.call(o, b);
      return o.desc * (a < b ? -1 : +(a > b));
    });
  };
  
}());

//--------------------------------------------------------
var aNumbers = [10,8,5,3,7,4,5,1];
var aObject = [
      {name: "david",  age: 30},
      {name: "Luis",   age: 24},
      {name: "julian", age: 24},
      {name: "alex",   age: 36},
      {name: "Samuel", age: 28},
      {name: "Diana",  age: 25}
    ];

console.warn("> NUMERIC ARRAY");
console.log(aNumbers);

// PROTOTYPE VERSION
console.info("ASCENDING ORDER");
console.log(aNumbers.sortBy());

// FUNCTION VERSION
console.info("DESCENDING ORDER");
sortBy(aNumbers, { desc: true });
console.log(aNumbers);

console.warn("> ARRAY OF OBJECTS");
console.log(aObject);

// PROTOTYPE VERSION
console.info("ASCENDING BY @age");
aObject.sortBy({ prop: "age" });
console.log([].concat(aObject));

// FUNCTION VERSION
console.info("DESCENDING BY @name (ignore case)");
sortBy(aObject, {
  prop: "name",
  desc: true,
  parser: function (item) {
    //ignore case sensitive
    return item.toUpperCase();
  }
});
console.log([].concat(aObject));

/* Sorts the array by Date
aObject.sortBy({
  prop: "dob",
  desc: true,
  parser: function (item) { return new Date(item); }
});
*/