#include "mainwindow.h"

#include "ui_mainwindow.h"

MainWindow::MainWindow(QWidget* parent)
    : QMainWindow(parent), ui(new Ui::MainWindow) {
  ui->setupUi(this);

  /**********ÀàÐÍת»»´íÎó**********/
  // 1.ÒþʽÀàÐÍת»»µ¼Öµľ«¶ÈËðʧ
  double numDouble = 3.1415926;
  int numInt = numDouble;  // Òþʽת»»£¬¾«¶ÈËðʧ£¬Ã»ÓнøÐÐÏÔʽ static_cast
  // int numInt = static_cast<int>(numDouble); // ÏÔʽת»»£¬Ã÷È·±íʾ½ÓÊܾ«¶ÈËðʧ
  // int numInt = (int)numDouble;

  // 2.Ç¿ÖÆÀàÐÍת»»´íÎó
  void* void_ptr = nullptr;
  int* int_ptr = static_cast<int*>(
      void_ptr);  // Ç¿ÖÆת»»´íÎó£¬void Ö¸Õë²»ÄÜÖ±½ÓתΪÓзûºÅÀàÐÍÖ¸Õë

  // 3.ת»»ÀàÐͺó×îºÃÅжÏÒ»ÏÂÊÇ·ñת»»³É¹¦£¬Ö¸ÕëÊÇ·ñΪ¿Õ

  /**********Âß¼­´íÎó**********/
  // 1.Ñ­»·ÎÞÍ˳öÌõ¼þ£¨ËÀÑ­»·£©
  for (int i = 0;; i++) {
    // Ñ­»·Ìå
  }
  // 2.Êý×éÔ½½ç
  int array[10];
  array[10] = 0;  // Ô½½ç·ÃÎÊÈÝÆ÷ÔªËØ
  std::vector<int> vec(5);
  vec[10] = 0;  // Ô½½ç·ÃÎÊÈÝÆ÷ÔªËØ

  // 3.Ìõ¼þÅжÏÖеÄÂß¼­ÔËËã·ûÎóÓã¨= ´úÌæ ==£©
  int a = 5, b = 10;
  if (a = b) {  // ÎóÓà = ´úÌæ ==£¬´Ë´¦Âß¼­¶Ì·£¬a ±»¸³ÖµÎª b µÄÖµ£¬Ìõ¼þΪÕæ
                // Ö´ÐдúÂë¿é
  }

  // 4.δ³õʼ»¯±äÁ¿µÄʹÓÃ
  int uninitialized;
  if (uninitialized > 0) {  // ʹÓÃδ³õʼ»¯±äÁ¿£¬¿ÉÄܵ¼ÖÂ䶨ÒåÐÐΪ
                            // Ö´ÐдúÂë¿é
  }

  /**********ÄÚ´æ¹ÜÀí´íÎó**********/
  // 1.ÒýÓÿÕÖ¸Õë
  int* ptr = new int[5];
  delete[] ptr;
  ptr[0] = 10;  // Ö¸ÕëÒÑÐü¿Õ£¬ÈÔ³¢ÊÔ·ÃÎÊ

  // 2.ÄÚ´æй¶
  int* pt = new int[10];
  // ûÓÐ delete[] pt

  /**********ÆäËû´íÎó**********/
  //δʹÓõıäÁ¿
  int unused = 0;
}

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