javascript获取url链接传递的指定参数值代码下载

<script>
function request(paras,url){
  //var url=location.href;
  var paraString=url.substring(url.indexOf("?") + 1, url.length).split("&");
  var paraObj = {}
  for (i=0;i<paraString.length;i++) {
    var j=paraString
    paraObj[j.substring(0,j.indexOf("=")).toLowerCase()]=j.substring(j.indexOf("=")+1,j.length);
  }
  var returnValue=paraObj[paras.toLowerCase()];
  if(typeof(returnValue)=="undefined") {
    return "";
  } 
  else {
    return returnValue;
  }
}
var urlStr="softwhy.com?a=1&b=2";
console.log(request("a",urlStr));
</script>