multiple questions (global variables and setText() for QLabel)

[Baxter]

from "mainScreen.h"

#ifndef __MAIN_H__
#define __MAIN_H__
#include <QMainWindow>
#include <QApplication>
#include <QPushButton>
#include <QDialog>
#include <cstdlib>
#include "main.cpp"
 
	// connects the code to the UI
class mainScreen : public :: QDialog, private Ui::mainScreenDLG
	{
		Q_OBJECT
 
	public:
		mainScreen(QDialog *parent = 0);
	};
 
 
#endif

#ifndef __MAIN_H__
#define __MAIN_H__
#include <QMainWindow>
#include <QApplication>
#include <QPushButton>
#include <QDialog>
#include <cstdlib>
#include "main.cpp"

	// connects the code to the UI
class mainScreen : public :: QDialog, private Ui::mainScreenDLG
	{
		Q_OBJECT
	 
	public:
		mainScreen(QDialog *parent = 0);
	};


#endif

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from "mainScreen.cpp"

#include <QApplication>
#include <QDataStream>
#include <QtGui>
#include <cstdlib>
#include <ctime>
#include "ui_mainScreen.h"
#include "mainScreen.h"
 
 
 
 
// code to begin the programme
mainScreen::mainScreen(QDialog *parent)
 
{
		setupUi(this); 
 
 
	// declaration of variables
	int operand1, operand2, divisi1, divisi2, sumAnswer, subAnswer, multiAnswer, divisiAnswer, i;
	bool selectSum, selectSub, selectMulti, selectDivisi;
 
	// timer for random generator
	srand (time(0));
 
		// selects which operations are being used
		if (selectSum = true)
		{
 
			operand1 = rand()/1638 + 1;
			operand2 = rand()/1638 + 1;
			lblOperand1.text()->setText(operand1);
			lblOperand2.text()->setText(operand2);
			sumAnswer = txtAnswer.text();
 
		}
		void mainScreen::on_btnCheck_clicked()
	{
	if (selectSum = true)
	{
		// if the correct answer is put in, then a message box shows this
		if (operand1 + operand2 == sumAnswer)
		{
			QMessageBox::about(this, "Correct!", "Correct!");
		}
 
		// if the incorrect answer is put in, then a message box shows this
		if (operand1 + operand2 != sumAnswer)
		{
			QMessageBox::about(this, "Incorrect", "Incorrect. The correct answer is" + sumAnswer); 
		}
	}
};

#include <QApplication>
#include <QDataStream>
#include <QtGui>
#include <cstdlib>
#include <ctime>
#include "ui_mainScreen.h"
#include "mainScreen.h"




// code to begin the programme
mainScreen::mainScreen(QDialog *parent)

{
		setupUi(this); 

	
	// declaration of variables
	int operand1, operand2, divisi1, divisi2, sumAnswer, subAnswer, multiAnswer, divisiAnswer, i;
	bool selectSum, selectSub, selectMulti, selectDivisi;

	// timer for random generator
	srand (time(0));
		
		// selects which operations are being used
		if (selectSum = true)
		{
		
			operand1 = rand()/1638 + 1;
			operand2 = rand()/1638 + 1;
			lblOperand1.text()->setText(operand1);
			lblOperand2.text()->setText(operand2);
			sumAnswer = txtAnswer.text();
			
		}
		void mainScreen::on_btnCheck_clicked()
	{
	if (selectSum = true)
	{
		// if the correct answer is put in, then a message box shows this
		if (operand1 + operand2 == sumAnswer)
		{
			QMessageBox::about(this, "Correct!", "Correct!");
		}
		
		// if the incorrect answer is put in, then a message box shows this
		if (operand1 + operand2 != sumAnswer)
		{
			QMessageBox::about(this, "Incorrect", "Incorrect. The correct answer is" + sumAnswer); 
		}
	}
};

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i want to make the text of lblOperand1 (which is a QLabel) the value of operand1
but i get the error

src/mainScreen.cpp:32: error: request for member ‘text’ in ‘((mainScreen*)this)->mainScreen::<anonymous>.Ui::mainScreenDLG::<anonymous>.Ui_mainScreenDLG::lblOperand1’, which is of non-class type ‘QLabel*’

src/mainScreen.cpp:32: error: request for member ‘text’ in ‘((mainScreen*)this)->mainScreen::<anonymous>.Ui::mainScreenDLG::<anonymous>.Ui_mainScreenDLG::lblOperand1’, which is of non-class type ‘QLabel*’

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i checked and made sure that the label was named and referenced to correctly

i also want to be able to use the "operand1" variable in "void mainScreen:n_btnCheck_clicked()"
but it tells me that the variables "selectSum", "operand1" etc are not declared in that scope?

thankyou in advance!!

[Qtbl]

Maybe "lblOperand1" is a pointer to a QLabel. Also try "lblOperand1.setText(QString("%1").arg(operand1)); "

"operand1" variable is a local variable not a class member.

[Lykurg]

assuming lblOperand1 is a valid pointer to your label, then you have to use

lblOperand1->setText("foo");

lblOperand1->setText("foo");

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with

lblOperand1->text();

lblOperand1->text();

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you get the current set text back, you can't mix those commands.

[Baxter]

"lblOperand1" is a QLabel, and I want its text value to be the contents of "operand1", an int
I also need "operand1" to be a global variable, so that i may reference it when "btnCheck" is clicked

[ChrisW67]

If lblOperand1 is a QLabel and not a pointer to one then:

lblOperand1.setText( QString::number(operand1) );
OR
lblOperand1.setText( QString("%1").arg(operand1) );

lblOperand1.setText( QString::number(operand1) );
OR
lblOperand1.setText( QString("%1").arg(operand1) );

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The mainScreen.cpp you have posted is mangled. It's not clear where your "global" variables are being declared. Are the existing declarations and the following code in the constructor? It certainly doesn't look like it belongs there. Your "global" variables should be class members if possible: they currently appear to be local variables in the constructor (as already pointed out).