Constant declarations are similar to the variable declarations described in Appendix C, “Variable Declarations.” The main differences are you must include an initialization statement to give the constant a value and you cannot change the value after the constant is initialized.
You may also need to use a literal type character to explicitly give a value’s type. For example, the following code attempts to create a float
constant and set its value to 5.8. Unfortunately, C# interprets the literal string 5.8 as a double
and not a float
, so Visual Studio flags this as an error.
const float taxRate = 5.8;
To avoid this problem, or to make your code more explicit, you can follow a literal value with a literal type character to indicate the value’s data type, as in the following code.
const float taxRate = 5.8F;
The following table lists C#’s literal type characters.
Character | Data Type |
U | uint |
L | long |
UL, LU | ulong |
F | float |
D | double |
M | decimal |
You can use either uppercase or lowercase for literal type characters.
You can also precede an integer literal with 0x or 0X to indicate that it is a hexadecimal value.
18.218.224.226