JS实现JSON.stringify的实例代码讲解

/**  * JSON stringify的实现  * @author norkts<norkts@gmail.com>  * @version 1.0 2015-11-24 15:11 实现了基本功能  * @version 1.1 2015-11-24 15:19 norkts 增加了JSON.stringify的兼用代码实现  * @version 1.2 2015-11-24 15:49 norkts 修改数组indexOf在IE下不兼容的写法,修改了undefined值的特殊处理  */ (function(NS){   //简单类型  var simpleTypes = ["number", "boolean", "undefined", "string", "function"];    //JSON.stringify的主函数  function stringify(object){   var type = typeof object;      //如果是简单类型，则直接返回简单类型的结果   if(indexOf(simpleTypes, type) > -1){    return parseSimpleObject(object);   }    //数组对象的   if(object instanceof Array){    var len = object.length;    var resArr = [];    for(var i = 0; i < len; i++){     var itemType = typeof object[i];     if(indexOf(simpleTypes, itemType) > -1){       //undefined特殊处理，数组中变成null      if(itemType != "undefined"){       resArr.push(parseSimpleObject(object[i]));      }else{       resArr.push("null");      }           }else{      //递归处理JS数组中的复杂元素      resArr.push(stringify(object[i]));     }    }        return "[" + resArr.join(",") + "]";   }      //普通object对象   if(object instanceof Object){    if(object == null){     return "null";    }        var resArr = [];        for(var name in object){     var itemType = typeof object[name];     if(indexOf(simpleTypes, itemType) > -1){      //undefined特殊处理，object中不编码      if(itemType != "undefined"){       resArr.push("/"" + name + "/":" + parseSimpleObject(object[name]));       }     }else{      resArr.push("/"" + name + "/":" + stringify(object[name]));     }    }        return "{" + resArr.join(",") + "}";   }  }    function parseSimpleObject(object){   var type = typeof object;   if(type == "string" || type == "function"){    return "/"" + object.toString().replace("/"", "///"") + "/"";   }      if(type == "number" || type == "boolean"){    return object.toString();   }      if(type == "undefined"){    return "undefined";   }      return "/"" + object.toString().replace("/"", "///"") + "/"";  }    function indexOf(arr, val){   for(var i = 0; i < arr.length; i++){    if(arr[i] === val){     return i;    }   }      return -1;  }    /**   * 将stringify做二次封装   * @param object 要处理的对象   *   */  NS.stringify = function(object, isEncodeZh){   var res = stringify(object);   if(isEncodeZh){    var encodeRes = "";    for(var i = 0; i < res.length; i++){     if(res.charCodeAt(i) < 0xff){      encodeRes += res[i];     }else{      encodeRes += "//u" + res.charCodeAt(i).toString(16);     }    }    res = encodeRes;   }      return res;  }; })(window);