Bool, Byte, Sbyte, Char, Int, Uint, Short, Ushort, Long, Ulong, String, Object, DECIMAL, DOUBLE, FLOAT
String, the default value of Object is null
Bool's default is False
The default value of other data types is equivalent to the value of 0, remember that the double is 0.0d, float is 0.0F, Decimal is 0.0m
Very strange why Decimal uses M to suffix
