js判断当前链接是否包含问好?js在当前链接追加参数

var deeplink_url = window.location.href; //获取当前链接
    if(deeplink_url.indexOf("?")!=-1) 
    {
    deeplink_url=deeplink_url+'&';
    }else{
        deeplink_url=deeplink_url+'?';
    } 
  deeplink_url=deeplink_url+'要添加的参数';