static void Main(string[] args)
{
var stack = new Stack();
const string menu = "\n1. Push\n2. Contains?\n3. Pop\n4. Clear\n5. Quit\n\nInput the number of menu: ";
string line;
var done = false;
GetLine(args, ref stack);
do
{
Console.Clear();
Console.WriteLine("Stack(" + stack.Count + "): " + (stack.ToString() != "" ? stack.ToString() : "null"));
Console.WriteLine(menu);
var key = Console.ReadLine();
switch (key)
{
case "1":
Console.Write("\nInput the line: ");
line = Console.ReadLine();
stack.Push(line);
break;
case "2":
Console.WriteLine("\nInput a line: ");
line = Console.ReadLine();
Console.WriteLine("\n" + stack.Contains(line));
Console.ReadLine();
break;
case "3":
stack.Pop();
break;
case "4":
stack.Clear();
break;
case "5":
done = true;
break;
case "6":
var a = stack.ToArray();
for (int i = 0; i < stack.Count; i++)
Console.WriteLine(a[i]);
Console.ReadLine();
break;
}
} while (!done);
}