QRegExp regExp(""); if(regExp.isEmpty()){ qDebug() << "Regular expression is empty"; }
QString pattern = "\\d"; QRegExp regExp(pattern); if(!regExp.isEmpty()){ qDebug() << "Regular expression is not empty"; }This code creates a regular expression with the pattern "\d" (which matches any digit) and checks if it is empty using the ! operator and the isEmpty() function. If it is not empty, it prints a message using the qDebug() function. Package/library: QRegExp is a part of the Qt Core module in the Qt framework of C++.