QUrl url("https://www.example.com/search?q=qt"); qDebug() << url.queryItemValue("q"); // Output: qt
QUrl url("https://www.example.com/search?q=qt&lang=en"); qDebug() << url.queryItemValue("lang"); // Output: en
QUrl url("https://www.example.com/"); qDebug() << url.queryItemValue("q"); // Output: ""This example creates a QUrl object for the URL "https://www.example.com/" and calls the queryItemValue function with the parameter "q". Since there is no query parameter with the name "q", the function returns an empty QString and prints it to the console using qDebug(). The QUrl class is part of the Qt Core library.