1.写一个函数 getQueryString,传入一个url地址和一个key,返回key对应的参数值 var url = 'https://wenku.baidu.com/0ea73.html?wkts=16784&query=email'; getQueryString(url,'query') => 'email' getQueryString(url,'wkts') => '16784'

function getQueryString(url, key) {
var reg = new RegExp("(^|&)" + key + "=([^&]*)(&|$)", "i");
var r = url.split("?")[1].match(reg);
if (r != null) return unescape(r[2]);
return null;
}

var url = 'https://wenku.baidu.com/0ea73.html?wkts=16784';
var key = 'wkts';
console.log(getQueryString(url, key)); // 输出 16784