Letter after a number, what is it called?

Question

What is this called?

double  d1 = 0d;
decimal d2 = 0L;
float   d3 = 0f;

And where can I find a reference of characters I can use? If I want

Answer 1

This

double  d1 = 0d;

is an example of a literal and the character after the digits is a suffix. There is not one for short. You need to cast:

short s = (short)0;

These are defined in 2.4.4 of the language specification, specifically 2.4.4.2 will tell you about integer literals where you will see that there is no way to express a short using a literal. Additionally, the integer-type-suffixes are:

U  u  L  l  UL  Ul  uL  ul  LU  Lu  lU  lu

which represent various signed/unsigned int/long types. Again, no way to express a short using literal.