I am working on a math trainer project. So, I must display int values from the array to QLCDNumber with delay. I used QTimer::singleshot but it delays only before the first number. Here is my code. What is the problem?
Qt Code: 
  1. #include "mainwindow.h"
  2. #include "ui_mainwindow.h"
  3. #include <QLCDNumber>
  4. #include <QTimer>
  5.  
  6. MainWindow::MainWindow(QWidget *parent) :
  7.     QMainWindow(parent),
  8.     ui(new Ui::MainWindow)
  9. {
  10.     ui->setupUi(this);
  11. }
  12.  
  13. MainWindow::~MainWindow()
  14. {
  15.     delete ui;
  16. }
  17.  
  18. void MainWindow::on_pushButton_clicked()
  19. {
  20.     int arr[] = {100,2,21,12};
  21.     for (int i = 0;i<4;i++) {
  22.         QTimer::singleShot(2000,this,[=]{
  23.            ui->lcdNumber->display(arr[i]);
  24.         });
  25.     }
  26. }
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