[Solved]How to generate random number between two numbers? Qt

Zain

Hello

Two numbers are taken as inputs & now I want to generate random number between them.

Please tell me how to do it?

Thanks
Zain

hpollak

You can use the cstdlib.

See: "cplusplus-doc":http://www.cplusplus.com/reference/cstdlib/rand/

Macro

Did u tried using qrand() ??

Bambo

random number from interval <a,b>: @x = a + rand() * (b-a)@

Macro

Example:

MainWindow.h
@
#include <QMainWindow>
class MainWindow : public QMainWindow
{
Q_OBJECT

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

private slots:
void on_pushButton_clicked();

private:
Ui::MainWindow *ui;
int High;
int Low;
};
@

MainWindow.cpp

@
#include "MainWindow.h"
#include "ui_MainWindow.h"
#include <qglobal.h>

MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
ui->setupUi(this);
High = 10;
Low = 5;
}

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

void MainWindow::on_pushButton_clicked()
{
qsrand(qrand());
ui->lineEdit->setText(QString::number(qrand() % ((High + 1) - Low) + Low));
}
@

Zain

Thank u all

Done with it.

tobias.hunger

Note that qrand produces pseudo-random number only. You do want to use something better for e.g. crypto operations.

Todd987

This post is deleted!

rsarov

modern Qt c++ 11

#include <random>
#include "QDateTime"

int getRand(int min, int max){
    unsigned int ms = static_cast<unsigned>(QDateTime::currentMSecsSinceEpoch());
    std::mt19937 gen(ms);
    std::uniform_int_distribution<> uid(min, max);    
    return uid(gen);
}

Vadi2

Or modern Qt: https://doc.qt.io/qt-5/qrandomgenerator.html :)