URL Parser

urlparser.js

var parser = function(url) {
  var a = document.createElement('a');
  a.href = url;
  
  var search = function(search) {
    if(!search) return {};
    
    var ret = {};
    search = search.slice(1).split('&');
    for(var i = 0, arr; i < search.length; i++) {
      arr = search[i].split('=');
      var key = arr[0], value = arr[1];
      if(/\[\]$/.test(key)) {
        ret[key] = ret[key] || [];
        ret[key].push(value);
      } else {
        ret[key] = value;
      }
    }
    return ret;
  };
  
  return {
    protocol: a.protocol,
    host: a.host,
    hostname: a.hostname,
    pathname: a.pathname,
    search: search(a.search),
    hash: a.hash
  }
};

var url = 'http://sub.example.com:8023/home/?foo=bar&ciao=cc&arr[]=1&arr[]=2#hash';
parser(url);

// 结果是？

a.pathname在chrome下是带开头的/的，IE下不带，a.port默认情况下IE是输出80的，而chrome是输出空字符串。。

      ^(([^:/?#]+):)?(//([^/?#]*))?([^?#]*)(\?([^#]*))?(#(.*))?
       12            3  4          5       6  7        8 9

   The numbers in the second line above are only to assist readability;
   they indicate the reference points for each subexpression (i.e., each
   paired parenthesis).  We refer to the value matched for subexpression
   <n> as $<n>.  For example, matching the above expression to

      http://www.ics.uci.edu/pub/ietf/uri/#Related

   results in the following subexpression matches:

      $1 = http:
      $2 = http
      $3 = //www.ics.uci.edu
      $4 = www.ics.uci.edu
      $5 = /pub/ietf/uri/
      $6 = <undefined>
      $7 = <undefined>
      $8 = #Related
      $9 = Related

https://tools.ietf.org/html/rfc3986#page-50