minimal deep copy in JavaScript

deepCopy.js

  function deepCopy(val) {
    if (Array.isArray(val)) return val.map(deepCopy);
    if (typeof val != "object" || val === null || val === undefined) return val; 
    var ret = {};
    for (var attr in val) if (val.hasOwnProperty(attr)) ret[attr] = deepCopy(val[attr]);
    return ret; 
  }