What does the "M" stand for in decimal value assignment?

Question

MSDN says:

"Without the suffix m, the number is treated as a double, thus generating a compiler error."

What does the "M" in:

decimal current = 10.99M; 

stand for?

Is it any different than:

decimal current = (decimal)10.99 

Answer 1

M makes the number a decimal representation in code.

To answer the second part of your question, yes they are different.

decimal current = (decimal)10.99 

is the same as

double tmp = 10.99; decimal current = (decimal)tmp; 

Now for numbers larger than sigma it should not be a problem but if you meant decimal you should specify decimal.

---

Update:

Wow, i was wrong. I went to go check the IL to prove my point and the compiler optimized it away.

---

Update 2:

I was right after all!, you still need to be careful. Compare the output of these two functions.

class Program {     static void Main(string[] args)     {         Console.WriteLine(Test1());         Console.WriteLine(Test2());         Console.ReadLine();     }      static decimal Test1()     {         return 10.999999999999999999999M;     }     static decimal Test2()     {         return (decimal)10.999999999999999999999;     } } 

The first returns 10.999999999999999999999 but the seccond returns 11

---

Just as a side note, double will get you 15 decimal digits of precision but decimal will get you 96 bits of precision with a scaling factor from 0 to 28. So you can represent any number in the range ((-2⁹⁶ to 2⁹⁶) / 10^{(0 to 28)})