#include "mainwindow.h"
#include "ui_mainwindow.h"
 #include <QLineEdit>
 #include <QString>

MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent), ui(new Ui::MainWindow)
{

    ui->setupUi(this);

}

MainWindow::~MainWindow()
{
    delete ui;
}

void MainWindow::on_pushButton_clicked()
{

    QLineEdit InputA;
    InputA.text()"Hallo";
}

void MainWindow::on_pushButton_clicked()
{

    QLineEdit InputA;
    InputA.text()"Hallo"; //Was soll das sein?
}

InputA.text()"Hallo";

Dieser Satz kein Verb.