深拷贝 浅拷贝问题

 1 var cloneObj = function(obj){
 2     var str, newobj = obj.constructor === Array ? [] : {};
 3     if(typeof obj !== ‘object‘){
 4         return;
 5     } else if(window.JSON){
 6         str = JSON.stringify(obj), //系列化对象
 7         newobj = JSON.parse(str); //还原
 8     } else {
 9         for(var i in obj){
10             newobj[i] = typeof obj[i] === ‘object‘ ? 
11             cloneObj(obj[i]) : obj[i]; 
12         }
13     }
14     return newobj;
15 };