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!

I don't see you using "c" anywhere.
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

Qt World Summit: Register Today!

Sum Variable Problem