1、代码：

void MainWindow::on_pushButton_clicked()
{
    QString str = "5";
    QString str01 = str.leftJustified(3, '0');
    qDebug() << str01;
    str01 = str.rightJustified(5, '0');
    qDebug() << str01;
    str01 = str.rightJustified(2, '0');
    qDebug() << str01;
}

 

2、控制台输出：

"500"
"00005"
"05"

 

3、

4、

5、

 

转载于:https://www.cnblogs.com/cppskill/p/8085270.html