Reference address: https://www.cnblogs.com/zouhao/p/7278117.html
function clone(obj) { // Handle the 3 simple types, and null or undefined if (null == obj || 'object' != typeof obj) { return obj }; // Handle Date if (obj instanceof Date) { var copy = new Date (); copy.setTime(obj.getTime()); return copy; } // Handle Array if (obj instanceof Array) { var copy = []; for (var i = 0, len = obj.length; i < len; i++) { copy[i] = clone(obj[i]); } return copy; } // Handle Object if (obj instanceof Object) { var copy = {}; for (var attr in obj) { if (obj.hasOwnProperty(attr)){ copy[attr] = clone(obj[attr]); } } return copy; } throw new Error('Unable to copy obj! Its type isn\'t supported.'); }