TIL you can reference PowerShell object properties using a variable containing the name

Song recommendation of the day

Screaming Females put on some of the best live shows I've been to.

The problem

I wrote a PowerShell script to generate markdown tables for the default permissions of Octopus Deploy's built-in user roles.

I ran into a snag matching the permissions granted to a role to their descriptions.

The object holding the descriptions looks like this:

$permissionDetails = @{
    EnvironmentEdit = @{
        Description = "Edit environment information"
    }
    EnvironmentView = @{
        Description = "View environment information"
    }
    TeamView        = @{
        Description = "View team information"
    }
    UserView        = @{
        Description = "View user information"
    }
}

The role has an array of permissions granted to it.

$grantedPermissions = @("TeamView", "UserView")

I need to iterate over this array and access the Description property of the permission property that matches the name.

The solution

How to do this was a gap in my PowerShell knowledge. My first few attempts did not work at all.

After a few searches, I found this solution. You can reference a property name using a string.

$obj."SomeProp"

If you can reference it using a string, maybe you can reference it using a variable?

foreach ($name in $grantedPermissions) {
    Write-Output $permissionDetails.$name.Description
}

That works!

I will definitely be using this trick in the future.

This post was originally published at blog.rousseau.dev. Cover photo by Sam Dan Truong on Unsplash.