do {
    code
} while (stuff);

do {
    code
} while (stuff);

keyword (stuff)
{
    code
}

keyword (stuff)
{
    code
}

while (true)
{
    Console.WriteLine("Type `quit` to quit");
    Console.WriteLine("Press enter to continue");
    selection = Console.ReadLine();
    if (selection == "quit")
    {
        break;
    }
    // all the other code
}

while (true)
{
    Console.WriteLine("Type `quit` to quit");
    Console.WriteLine("Press enter to continue");
    selection = Console.ReadLine();
    if (selection == "quit")
    {
        break;
    }
    // all the other code
}

string selection;
do {
    Console.WriteLine("Type `quit` to quit");
    Console.WriteLine("Press enter to continue");
    selection = Console.ReadLine();
    // all the other code    
} while (selection != "quit");

string selection;
do {
    Console.WriteLine("Type `quit` to quit");
    Console.WriteLine("Press enter to continue");
    selection = Console.ReadLine();
    // all the other code    
} while (selection != "quit");