简单的js深拷贝

代码如下

  function deepCopy(o, n) {
    for (var i in n) {
        if (typeof n[i] == 'object') {
            o[i] = n[i].constructor == Array ? [] : {};
            deepCopy(o[i], n[i]);
        } else {
            o[i] = n[i];
        }
    }
    return o;
}

测试:

var a = {};
var b = {
   num: 30,
   arr: [9, 23],
   obj: {
       'year': 2017,
       "lover": "qingjie"
   }
};
deepCopy(a, b);

a.arr.push(3);
console.log(a);
/*
{ 
 num: 30,
 arr: [ 9, 23 ,3],
 obj: { 
   year: 2017, 
   lover: 'qingjie' 
  }
}
*/

console.log(b);
/*
{ 
 num: 30,
 arr: [ 9, 23 ],
 obj: { 
   year: 2017, 
   lover: 'qingjie' 
  }
}
*/