Variables and Data Types

#include <iostream>
using namespace std;

int main() {

    bool isValid = true;

    cout << boolalpha << isValid << endl;

    int myInt;
    myInt = 42;
    double myDouble = 3.14159;

    cout << myInt << endl;
    cout << myDouble << endl;

    const double MY_PI = 3.14159;	// Capitalized Snake-case or Capitalized-underscore case

    return 0;
}