3 实现对象的深拷贝

 var china = {
          nation : '中国',
          birthplaces:['北京','上海','广州'],
          skincolr :'yellow',
          friends:['sk','ls']
      }
      //深复制，要想达到深复制就需要用递归
      function deepCopy(o,c){
        var c = c || {}
        for(var i in o){
        if(typeof o[i] === 'object'){
                          //要考虑深复制问题了
                      if(o[i].constructor === Array){
                        //这是数组
                        c[i] =[]
                    }else{
                        //这是对象
                        c[i] = {}
                    }
                    deepCopy(o[i],c[i])
                    }else{
                         c[i] = o[i]
                    }
             }
             return c
      }
      var result = {name:'result'}
      result = deepCopy(china,result)
      console.dir(result)

json

 var test ={
          name:{
           xing:{ 
               first:'张',
               second:'李'
          },
          ming:'老头'
      },
      age :40,
      friend :['隔壁老王','宋经纪','同事']
     }
      var result = JSON.parse(JSON.stringify(test))
      result.age = 30
      result.name.xing.first = '往'
      result.friend.push('fdagldf;ghad')
      console.dir(test)
      console.dir(result)