[Qt] Calculator

코드

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>

QT_BEGIN_NAMESPACE
namespace Ui { class MainWindow; }
QT_END_NAMESPACE

class MainWindow : public QMainWindow
{
    Q_OBJECT

public:
    MainWindow(QWidget *parent = nullptr);
    ~MainWindow();

private slots:
    void on_pushButton_1_clicked();

    void on_pushButton_3_clicked();

    void on_pushButton_7_clicked();

    void on_pushButton_2_clicked();

    void on_pushButton_4_clicked();

    void on_pushButton_5_clicked();

    void on_pushButton_6_clicked();

    void on_pushButton_8_clicked();

    void on_pushButton_9_clicked();

    void on_pushButton_0_clicked();

    void on_pushButton_plus_clicked();

    void on_pushButton_minors_clicked();

    void on_pushButton_mul_clicked();

    void on_pushButton_div_clicked();

    void on_pushButton_clear_clicked();

    void on_pushButton_exit_clicked();

    void on_pushButton_equal_clicked();

private:
    Ui::MainWindow *ui;
    void setNumer(QString num);     // 일반함수
};
#endif // MAINWINDOW_H

#include "mainwindow.h"
#include "ui_mainwindow.h"

MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent)
    , ui(new Ui::MainWindow)
{
    ui->setupUi(this);
}

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


void MainWindow::on_pushButton_1_clicked()
{
    setNumer("1");
}

void MainWindow::on_pushButton_2_clicked()
{
    setNumer("2");
}

void MainWindow::on_pushButton_3_clicked()
{
    setNumer("3");
}

void MainWindow::on_pushButton_4_clicked()
{
    setNumer("4");
}

void MainWindow::on_pushButton_5_clicked()
{
    setNumer("5");
}

void MainWindow::on_pushButton_6_clicked()
{
    setNumer("6");
}

void MainWindow::on_pushButton_7_clicked()
{
    setNumer("7");
}

void MainWindow::on_pushButton_8_clicked()
{
    setNumer("8");
}

void MainWindow::on_pushButton_9_clicked()
{
    setNumer("9");
}

void MainWindow::on_pushButton_0_clicked()
{
    setNumer("0");
}

void MainWindow::on_pushButton_plus_clicked()
{
    ui -> lineEdit_2 -> setText("+");
}

void MainWindow::on_pushButton_minors_clicked()
{
    ui -> lineEdit_2 -> setText("-");

}

void MainWindow::on_pushButton_mul_clicked()
{
    ui -> lineEdit_2 -> setText("*");
}

void MainWindow::on_pushButton_div_clicked()
{
    ui -> lineEdit_2 -> setText("/");
}

void MainWindow::on_pushButton_equal_clicked()
{
    if (ui -> lineEdit_2 -> text() == "+")
        ui -> lineEdit_4 -> setText(QString::number(ui->lineEdit_1->text().toInt(NULL, 10) + ui->lineEdit_3->text().toInt(NULL, 10)));
    else if (ui -> lineEdit_2 -> text() == "-")
        ui -> lineEdit_4 -> setText(QString::number(ui->lineEdit_1->text().toInt(NULL, 10) - ui->lineEdit_3->text().toInt(NULL, 10)));
    else if (ui -> lineEdit_2 -> text() == "*")
        ui -> lineEdit_4 -> setText(QString::number(ui->lineEdit_1->text().toInt(NULL, 10) * ui->lineEdit_3->text().toInt(NULL, 10)));
    else if (ui -> lineEdit_2 -> text() == "/")
        ui -> lineEdit_4 -> setText(QString::number(ui->lineEdit_1->text().toInt(NULL, 10) / ui->lineEdit_3->text().toInt(NULL, 10)));
}
void MainWindow::on_pushButton_clear_clicked()
{
    ui -> lineEdit_1 -> setText("");
    ui -> lineEdit_2 -> setText("");
    ui -> lineEdit_3 -> setText("");
    ui -> lineEdit_4 -> setText("");
}

void MainWindow::on_pushButton_exit_clicked()
{
    this -> close();
}

void MainWindow::setNumer(QString num)
{
    if (QString::compare(ui -> lineEdit_2 -> text(), "") == 0) // 라인에디트3을 읽어서 비교 ""라면 0을 return
    {
        ui -> lineEdit_1 -> setText((ui ->lineEdit_1) -> text() + num);
    }
    else
    {
        ui -> lineEdit_3 -> setText((ui ->lineEdit_3) -> text() + num);
    }
}

동작영상