Weird Symbols when using toInt()

[020394]

Hello Guys,
I been facing a problem lately with toInt() conversion, I get wierd symbols in the label i link the toInt() to . I get "@!" and sometimes the whole string of event handler comes out for eg "void Calculator:n_Num7_clicked()"
The following are my codings
.h

#ifndef CALCULATOR_H
#define CALCULATOR_H
 
#include <QWidget>
 
#include <QDebug>
#include <QtCore>
#include<QtGui>
 
namespace Ui {
class Calculator;
}
 
class Calculator : public QWidget
{
    Q_OBJECT
 
public:
    explicit Calculator(QWidget *parent = 0);
    ~Calculator();
 
private slots:
    void on_Num1_clicked();
 
    void on_Num2_clicked();
 
 
    void on_Add_clicked();
 
 
 
private:
    Ui::Calculator *ui;
};
 
#endif // CALCULATOR_H

#ifndef CALCULATOR_H
#define CALCULATOR_H

#include <QWidget>

#include <QDebug>
#include <QtCore>
#include<QtGui>

namespace Ui {
class Calculator;
}

class Calculator : public QWidget
{
    Q_OBJECT
    
public:
    explicit Calculator(QWidget *parent = 0);
    ~Calculator();
    
private slots:
    void on_Num1_clicked();

    void on_Num2_clicked();


    void on_Add_clicked();

  

private:
    Ui::Calculator *ui;
};

#endif // CALCULATOR_H

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.cpp

#include "calculator.h"
#include "ui_calculator.h"
int num1=0;
QString str;
 
 
 
Calculator::Calculator(QWidget *parent) :
    QWidget(parent),
    ui(new Ui::Calculator)
{
    ui->setupUi(this);
    ui->lineEdit->setText("");
 
}
 
Calculator::~Calculator()
{
    delete ui;
}
 
void Calculator::on_Num2_clicked()
{
    ui->lineEdit->setText(ui->lineEdit->text()+"2");
}
 
 
void Calculator::on_Add_clicked()
{
 
   str=ui->lineEdit->text();
   num1=str.toInt();
   ui->label->setText(""+num1);
qDebug()<<num1;
 
}

#include "calculator.h"
#include "ui_calculator.h"
int num1=0;
QString str;



Calculator::Calculator(QWidget *parent) :
    QWidget(parent),
    ui(new Ui::Calculator)
{
    ui->setupUi(this);
    ui->lineEdit->setText("");

}

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

void Calculator::on_Num2_clicked()
{
    ui->lineEdit->setText(ui->lineEdit->text()+"2");
}


void Calculator::on_Add_clicked()
{
    
   str=ui->lineEdit->text();
   num1=str.toInt();
   ui->label->setText(""+num1);
qDebug()<<num1;

}

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The qDebug() works perfectly fine , it is able to show the numbers
Thank you in advance

[stampede]

You add integer to string constant in line 33. I don't think this is what you wanted.
Use QString class methods to convert numbers to strings (QString::number, ::arg, ::setNum)