how resize the Qwidget objects within a window

[vinayaka]

i coded like this . if this is stupid forgive me okay

//////////day25.cpp
#include "day25.h"
#include "ui_day25.h"
#include "widget.h"
 
 
day25::day25(Widget *parent) :
    Widget(parent),
    ui(new Ui::day25)
{
 
    ui->setupUi(this);
    //int num=100;
    QString qStr = QString::number(num);
    ui->label_2->setText(qStr);
 
 
}
 
day25::~day25()
{
    delete ui;
}
 
////////////widget.cpp
#include "widget.h"
#include "ui_widget.h"\
#include "day25.h"
//#include<QString>
 
Widget::Widget(QWidget *parent) :
    QWidget(parent),
    ui(new Ui::Widget)
{
    ui->setupUi(this);
    //QString n;
    //n=ui->lineEdit->text();
    QString str;
    float num;
    str=ui->lineEdit->text();
    num=str.toInt();
 
}
 
Widget::~Widget()
{
    delete ui;
}
 
void Widget::on_pushButton_3_clicked()
{
   day25 *k=new day25;
   k->show();
   this->hide();
 
 
}
 
//////day25.h
#ifndef DAY25_H
#define DAY25_H
 
#include <QWidget>
#include "widget.h"
 
namespace Ui {
    class day25;
}
 
class day25 : public Widget
{
    Q_OBJECT
 
public:
    explicit day25(Widget *parent = 0);
    ~day25();
 
private:
    Ui::day25 *ui;
};
 
#endif // DAY25_H
 
/////widget.h
#ifndef WIDGET_H
#define WIDGET_H
 
#include <QWidget>
 
namespace Ui {
    class Widget;
}
 
class Widget : public QWidget
{
    Q_OBJECT
 
public:
    explicit Widget(QWidget *parent = 0);
    ~Widget();
 
private:
    Ui::Widget *ui;
 
private slots:
    void on_pushButton_3_clicked();
};
 
#endif // WIDGET_H

//////////day25.cpp
#include "day25.h"
#include "ui_day25.h"
#include "widget.h"


day25::day25(Widget *parent) :
    Widget(parent),
    ui(new Ui::day25)
{

    ui->setupUi(this);
    //int num=100;
    QString qStr = QString::number(num);
    ui->label_2->setText(qStr);


}

day25::~day25()
{
    delete ui;
}

////////////widget.cpp
#include "widget.h"
#include "ui_widget.h"\
#include "day25.h"
//#include<QString>

Widget::Widget(QWidget *parent) :
    QWidget(parent),
    ui(new Ui::Widget)
{
    ui->setupUi(this);
    //QString n;
    //n=ui->lineEdit->text();
    QString str;
    float num;
    str=ui->lineEdit->text();
    num=str.toInt();

}

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

void Widget::on_pushButton_3_clicked()
{
   day25 *k=new day25;
   k->show();
   this->hide();


}

//////day25.h
#ifndef DAY25_H
#define DAY25_H

#include <QWidget>
#include "widget.h"

namespace Ui {
    class day25;
}

class day25 : public Widget
{
    Q_OBJECT

public:
    explicit day25(Widget *parent = 0);
    ~day25();

private:
    Ui::day25 *ui;
};

#endif // DAY25_H

/////widget.h
#ifndef WIDGET_H
#define WIDGET_H

#include <QWidget>

namespace Ui {
    class Widget;
}

class Widget : public QWidget
{
    Q_OBJECT

public:
    explicit Widget(QWidget *parent = 0);
    ~Widget();

private:
    Ui::Widget *ui;

private slots:
    void on_pushButton_3_clicked();
};

#endif // WIDGET_H

To copy to clipboard, switch view to plain text mode 

error:num is not declared in this scope.
if command is removed answer is always 100
plz help meeeeeeeeee