js获取当前url地址中的参数

function getUrlParam(name){
    var reg = new RegExp("(^|&)"+ name +"=([^&]*)(&|$)");
    var r = window.location.search.substr(1).match(reg);
    if(r!=null)
        return decodeURI(r[2]);
    return null;
}
console.log(getUrlParam("id"));//结果：18

function getUrlParam(name) {
    var reg = new RegExp("(^|&)" + name + "=([^&]*)(&|$)", "i");
    var reg_rewrite = new RegExp("(^|/)" + name + "/([^/]*)(/|$)", "i");
    var r = window.location.search.substr(1).match(reg);
    var q = window.location.pathname.substr(1).match(reg_rewrite);
    if(r != null){
        return decodeURI(r[2]);
    }else if(q != null){
        return decodeURI(q[2]);
    }else{
        return null;
    }
}
console.log(getUrlParam("id"));//结果：18