js中的深克隆与浅克隆

浅克隆：原始类型按值传递，对象类型按引用传递，与原对象共用一处内存，修改会使原对象也修改

 1 var lilei={
 2     sname:"li lei",
 3     sage:12,
 4     address:{
 5       city:"xian",
 6       street:"未央区"
 7     }
 8   }
 9   function clone(oldObj){
10     if(oldObj==null){return null};
11     if(typeof oldObj!=="Object"){return oldObj}
12     var newObj = Array.isArray(oldObj)?[]:{};
13     for(var key in oldObj){
14       newObj[key] = oldObj[key]
15     }
16     return newObj;
17   }
18   var lilei2 = clone(lilei);
19   console.log(lilei===lilei2)//true
20   console.log(lilei);
21   console.log(lilei2)
22   lilei2.sname="李雷"
23   console.log(lilei.sname);//李雷
24   lilei2.address.city="beijing";
25   console.log(lilei.address.city);//beijing 很明显原对象的属性值已被修改

深克隆：在内存中开辟一块新内存，将原对象中的所有值全部复制过去，与原对象完全脱离，修改新对象中的属性值不会影响原对象、

 1 var hmm={
 2     sname:"han meimei",
 3     sage:15,
 4     address:{
 5       city:"shenzhen",
 6       street:"林湖区"
 7     }
 8   }
 9   function clone2(oldObj){
10     var newObj = Array.isArray(oldObj)?[]:{};
11     for(var key in oldObj){
12       if(typeof oldObj[key] !=="object"){
13         newObj[key]=oldObj[key]
14       }else{
15         newObj[key]=clone2(oldObj[key])
16       }
17     }
18     return newObj;
19   }
20   var hmm2=clone2(hmm);
21   console.log(hmm,hmm2);
22   console.log(hmm===hmm2);//false 
23   hmm2.sname="韩梅梅"
24   hmm2.address.city="xian";
25   console.log(hmm.sname);//还是han meimei 原对象没变
26   console.log(hmm.address.city);//还是shenzhen 原对象没变