Definition: Declares constants for use in place of literal values.
A constant is nothing more than a variable whose value cannot be changed while a script is running. In Windows PowerShell you can define a constant by using the Set-Variable Cmdlet and specifying three parameters:
· -name, the name of the constant (don’t include the $).
· -value, the value of the constant.
· -optionconstant, to create a constant as opposed to a standard variable.
For example, this command creates a constant named $ForReading, with a value of 1:
If you try to assign a new value to this constant you’ll get an error message similar to this: