var book = {

            title:"JavaScript Learn",

            author:["wang","jie"],

            edition:3,

            year:2015,

            releaseDate:new Date(2015,10,29)

        }

        var jsonText  = JSON.stringify(book)

        var bookCopy = JSON.parse(jsonText,function(key,value){

            if(key =="releaseDate"){

                return new Date(value);

            }else{

                return value;

            }

        })

        alert(bookCopy.releaseDate.getFullYear());