JavaScript实现url参数转成json形式

朋友问的一个面试题：有个url，要求获取url 的参数，返回值为json格式。
简单的写了下，发笔记备份。

<！DOCTYPE html><html><head> <meta charset="utf-8"> <title>simple a example for url to json</title> <script> var url = "https://www.baidu.com/s?ie=utf-8&f=8&rsv_bp=0&rsv_idx=1&tn=baidu&wd=慕课&rsv_pq=e379bd8200001a8c&rsv_t=ea8cxrgm03IFb44zHA261P6KziPRXAekcjwsRJtUSKLUmKweFsZFXE%2BUSrU&rqlang=cn&rsv_enter=0&rs"; function url2json（url）{var index = -1, str = "", arr = [], length = 0, res = {};if（url.indexOf（"?"）！=-1）{index = url.indexOf（"?"）;str = url.substring（index+1）;arr = str.split（"&"）;length = arr.length;for（var i=0; i<length-1; i++）{ res[arr[i].split（"="）[0]] = arr[i].split（"="）[1];}}else{res = {};}return res; }; var result = url2json（url）; //获取json的键值对条数（模拟长度） var length = 0; for（var i in result）{length++; } //在页面输出 var tL = 0; document.write（"{<br>"）; for（var name in result）{tL++;if（tL == length）{document.write（"  "+name+":"+result[name]+"<br>"）;}else{document.write（"  "+name+":"+result[name]+",<br>"）; } } document.write（"}"）; </script></head><body>