MSDN says:
\"Without the suffix m, the number is treated as a double, thus generating a compiler error.\"
What does the \"M\" in:
decimal curren
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))