Sum Variable Problem

[Semara123]

excuse me sorry i want to ask im a newbie want to learn Qt but i have some problem

i want to make Sum Variable that it will sum the variable and print it to the lineedit

here for mainwindow.cpp

#include "mainwindow.h"
#include "ui_mainwindow.h"
MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);
     ui->label->setNum(0);
}

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

void MainWindow::on_pushButton_clicked()
{
    ui->label->setText("SempAK Naga Jantan :v");
}



void MainWindow::on_pushButton_2_clicked()
{
    int a,b,c;
    a= 2;
    b= 2;
    c=a+b;

    //QString hasil = "";
    ui->label->setNum(QString::number(ui->lineEdit->text()));
    //ui->label->text().toInt();
}

i already watch the tutorial on youtube but i still dont understand , whats wrong in my code T_T

Thanks for help

Sorry for my bad english

[m.sue]

Hi,
setNum expects to get a number, you give it QString::number(ui->lineEdit->text()) which is a QString. And QString::number itself expects a number, you give it ui->lineEdit->text()which is a QString.
-Michael.

[BjornW]

What does the compiler say? It's usually a good place to start :-)

[Buckwheat]

@Semara123 ... Welcome!

1. I don't see you using "c" anywhere.
2. Try using ui->label->setNum (ui->lineEdit->text ().toInt ());

For more information on QString goto:
http://doc.qt.io/qt-5/qstring.html

Don't get discouraged. Qt is a large API and we all ask questions (even those of us who have been doing this for decades!) about it when we have problems. Good luck and have fun learning!

[Semara123]

@Buckwheat said in Sum Variable Problem:

ui->label->setNum (ui->lineEdit->text ().toInt ());

i already did it as you said but nothing happened :(

here is the code

#include "mainwindow.h"
#include "ui_mainwindow.h"
MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);
     ui->label->setNum(0);
}

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

void MainWindow::on_pushButton_clicked()
{
    ui->label->setText("SempAK Naga Jantan :v");
}



void MainWindow::on_pushButton_2_clicked()
{
    int a,b,c;
    a= 2;
    b= 2;
    c=a+b;

    //QString hasil = "";
    ui->label->setNum (ui->lineEdit->text().toInt());
    //ui->label->text().toInt();
}

Sorry to bother you T_T

and sorry for my bad english

[m.sue]

Hi,
so what would you want in ui->label? The value of c, then just write ui->label->setNum(c).
-Michael.

[Buckwheat]

@m-sue ... If that is the intent! Otherwise you are just adding a number for the sake of adding a number! And to top it off, it is a local variable so the compiler will most likely throw it away during optimization

[Semara123]

well now i already found the solution i forgot to delete this

case 2: _t->on_label_windowIconTextChanged((*reinterpret_cast< const QString(*)>(_a[1]))); break;

in moc_mainwindow.cpp 

now everything runs normally

thank you everybody for helping me to fix this problem :D

[mrjj]

@Semara123 said in Sum Variable Problem:

moc_mainwindow.cpp

This is a generated file so running qmake will recreate it.
So hopefully it wont come back :)

[Buckwheat]

@Semara123 ... you are manually editing your moc_ file? Wow! Ballsy! I just let the qmake regen it for me after I change my code. :D

[Semara123]

@Buckwheat said in Sum Variable Problem:

@Semara123 ... you are manually editing your moc_ file? Wow! Ballsy! I just let the qmake regen it for me after I change my code. :D

LOL i think i didnt do anything :v, but i want to say thanks to you for helping me :D and thanks for other people :D