How to add style via setStyleSheet() without losing orignal style in Qt?

Question

I Konw I can use setStyleSheet() to set style in Qt.But I encountered a problem,when I used setStyleSheet() twice first styles lost,which a

Answer 1

By using double column for the second entry.

ui->pushButton_2->setStyleSheet(
            "QPushButton{background-color:red;color:white}\
             QPushButton::hover{color:black}");