copy

 1 <script type="text/html">
 2     var obj1 = {
 3         'name': '撩课',
 4         'age': 2
 5     };
 6     var obj2 = {};
 7 
 8     for(var key in obj1){
 9         obj2[key] = obj1[key];
10     }
11     obj1.age = 30;
12     console.log(obj1);
13     console.log(obj2);
14 
15 </script>

<script type="text/html">
    var obj1 = {
        'name': '撩课',
        'age': 2
    };
    var obj2 = {};

    Object.assign(obj2, obj1);//合并
    obj2.age = 100;
    console.log(obj1);
    console.log(obj2);
</script>

The above two kinds is shallow copy

. 1 <Script>
 2      var P = {
 . 3          'name': 'John Doe' ,
 . 4          'Qucik Facts Pets': [ 'ha', 'Cai', 'Want small' ]
 . 5      };
 . 6  
. 7      var copyP = {};
 . 8      Object.assign (copyP, P);
 . 9  
10      p.pets.push ( 'I I nice and large river' );
 . 11      the console.log (copyP);
 12 is      the console.log (P);
 13 is </ Script>
 14  
15 will increase, affecting the original data

Deep copy

. 1 <Script>
 2      var obj = {
 . 3          name: 'stitch courses' ,
 . 4          Age: 18 is ,
 . 5          Friends: [ 'flower', 'black' ],
 . 6          goodF: {
 . 7              name: 'Small stitch' ,
 . 8              Age :. 19 ,
 . 9              address: 'Shanghai' ,
 10              Qucik Facts Pets: [{name: 'potatoes'}, {name: 'potato' }]},
 . 11          BIR: new new a Date ()
 12 is      };
 13 is  
14      var newobj =The JSON.parse (the JSON.stringify (obj));
 15  　　by such a deep copy is, will not affect each
 16      obj.goodF.pets [0] .name = 'ha ha ha ha' ;
 . 17      the console.log (newobj);
 18 is      the console.log (obj);
 . 19  
20 is      // regardless of change new, old and defects do not affect each other (do recursive) 
21 is </ Script>

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