Different Ways to Initialize Variables in C++

//Different ways to declare variables

#include <iostream>

using namespace std;

int main()
{

  /Ints
  int i1 = 1;
  cout << "i1 = " << i1 << endl;
  int i2;
  i2 = 2;
  cout << "i2 = " << i2 << endl;
  int i3(3);
  cout << "i3 = " << i3 << endl;
  int i4{ 4 };
  cout << "i4 = " << i4 << endl;

  //doubles
  double d1 = 3.3;
  double d2 = 11;


  //chars
  char c1 = 'a';
  cout << "ci = " << c1 << endl;

  bool flag = false;

  auto a1 = 1; //int
  auto a2 = 3.3; //double
  auto a3 = 'c';  //char
  auto a4 = "hello";  //c*
  auto a5 = true;  //bol
  auto a6 = 3L; //Long
  auto a7 = 1'000'000'000'000; //Long Long
  auto a8 = 0xFF; //int (255) hex literal
  auto a9 = 0b111; //int (7) binary literal

return 0;
}