JS实现JSON.stringify的实例代码讲解

/**

 * JSON stringify的实现

 * @author norkts

 * @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

 varsimpleTypes = ["number","boolean","undefined","string","function"];

 //JSON.stringify的主函数

 functionstringify(object){

  vartype =typeofobject;

  //如果是简单类型，则直接返回简单类型的结果

  if(indexOf(simpleTypes, type) > -1){

   returnparseSimpleObject(object);

  }

  //数组对象的

  if(objectinstanceofArray){

   varlen = object.length;

   varresArr = [];

   for(vari = 0; i < len; i++){

    varitemType =typeofobject[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(objectinstanceofObject){

   if(object ==null){

    return"null";

   }

   varresArr = [];

   for(varnameinobject){

    varitemType =typeofobject[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(",") +"}";

  }

 }

 functionparseSimpleObject(object){

  vartype =typeofobject;

  if(type =="string"|| type =="function"){

   return"\""+ object.toString().replace("\"","\\\"") +"\"";

  }

  if(type =="number"|| type =="boolean"){

   returnobject.toString();

  }

  if(type =="undefined"){

   return"undefined";

  }

  return"\""+ object.toString().replace("\"","\\\"") +"\"";

 }

 functionindexOf(arr, val){

  for(vari = 0; i < arr.length; i++){

   if(arr[i] === val){

    returni;

   }

  }

  return-1;

 }

 /**

  * 将stringify做二次封装

  * @param object 要处理的对象

  *

  */

 NS.stringify =function(object, isEncodeZh){

  varres = stringify(object);

  if(isEncodeZh){

   varencodeRes ="";

   for(vari = 0; i < res.length; i++){

    if(res.charCodeAt(i) < 0xff){

     encodeRes += res[i];

    }else{

     encodeRes +="\\u"+ res.charCodeAt(i).toString(16);

    }

   }

   res = encodeRes;

  }

  returnres;

 };

})(window);