System C# by API

using System;
using System.Collections.Generic;
using System.Text;
class Program {
    static void Main(string[] args) {
        Console.WriteLine(12.GetHashCode());
        Console.WriteLine(12.Equals(23));
        Console.WriteLine(12.GetType().BaseType);
        Console.WriteLine(12.ToString());
        Console.WriteLine(12); // ToString() called automatically.
    }
}