How to Use Enum in PowerShell

Tagged: PowerShell

Enum Definition#

In PowerShell, Enum or Enumeration is a data type that consists of named constants. Each of constants represents a value whose underlying type is integral numeric type.

Benefits of Enum#

There are some benefits of using Enum:

• Improved readability: Enums make your code more self-explanatory by assigning meaningful names to a set of related values. This can make your code easier to understand and maintain.
• Strongly-typed code: Enums are strongly-typed, which means the compiler checks the type correctness of assignments and comparisons. This helps catch errors early during the compilation process.
• IntelliSense support: Many IDE or text editor typically provides IntelliSense support. This means you get autocompletion suggestions and tooltips when using Enums, reducing the possibility of making errors.

How to Use Enum#

To define an Enum in PowerShell, you can use the enum keyword followed by the enumeration name and a pair of curly braces enclosing the enumeration values:

enum Color {
    Red
    Green
    Blue
}

In this example, we define an Enum named Color with three enumeration values: Red, Green, and Blue.

To use the Enum, simply refer to the Enum type and its values using the double-colon (::) operator:

$color = [Color]::Green

Here is a more complex example:

enum ErrorCode {
    NotFound = 404
    BadRequest = 400
    InternalServerError = 500
}

function Get-HttpStatusDescription {
    param ([ErrorCode] $ErrorCode)

    switch ($ErrorCode) {
        ([ErrorCode]::NotFound) { return "Not Found" }
        ([ErrorCode]::BadRequest) { return "Bad Request" }
        ([ErrorCode]::InternalServerError) { return "Internal Server Error" }
    }
}

$errorCode = [ErrorCode]::NotFound
$description = Get-HttpStatusDescription -ErrorCode $errorCode
Write-Host "Error Code: $errorCode, Description: $description"

In this example, we define an Enum called ErrorCode for HTTP status codes. We then use the Enum in a function called Get-HttpStatusDescription that takes an ErrorCode as a parameter and returns its description.