截取get请求的函数

getParameterByName =  function (a,url) {
    a = a.replace(/[\[]/, "\\[").replace(/[\]]/, "\\]");
    var c = new RegExp("[\\?&]" + a + "=([^&#]*)"), b = c.exec(location.search);
    if(url){
        b = c.exec(url);
    }
    return b == null ? "" : decodeURIComponent(b[1].replace(/\+/g, " "))
}
两个参数，一个是你需要截取的字段，一个是get请求网址
 
getParameterByName("fr","https://baike.baidu.com/item/jpgraph/5253147?fr=aladdin")//aladdin