how to concatenate a variable with a string

hi i am trying to concatenate a variable with a string. How can i do this?
here is the code

Code:

---

void login::show_user()
{
    QString user_name = user->text();
    QMessageBox::information(this, tr("Your Username"),
                             tr("Your username is user_name"));
}

---

i want to concatenate user_name in QMessageBox to display username

You can simply use + operator, or opt of string arguments..
QString message = "Your user name is " + user_name;
QString message = QString("Your user name is %1").arg(user_name).

Do read Qt Assistant..it helps