CODEWITHSUNDEEP
powershellnullhashtable
Grant Curell
Grant Curell

Reputation: 1763

PowerShell hashtable reference returns null

Null Output

Based on the above example, why would the result of the above not be 'On'? I'm feeling rather foolish because this is so simple but in any other language $PowerStateMap[$DeviceStatus.PowerState] would have returned 'On'. Does PowerShell have some weird trick for referencing a hashtable?

Update: I figured it out... I had to typecast $DeviceStatus.PowerState to an int manually. Why did I have to do that?

Edit: For reference:

enter image description here

Upvotes: 0

Views: 952

Answers (1)

AdminOfThings
AdminOfThings

Reputation: 25001

The problem is you are dealing with two different numeric types. The hash table contains keys of type Int32. The referenced object contains Int64 values. The simple solution is to just cast the Int64 values as Int32 when a hash table value is retrieved.

$PowerStateMap[[int]$DeviceStatus.PowerState]

We can simulate the above with an example:

$PowerStateMap = @{
    20 = 'Powering On'
    18 = 'Off'
    17 = 'On'
    21 = 'Powering Off'
}
$DeviceStatus = [pscustomobject]@{PowerState = [int64]17}

$DeviceStatus.PowerState
$DeviceStatus.PowerState.GetType()

"Testing Without Casting"
$PowerStateMap[$DeviceStatus.PowerState]
"Testing with casting"
$PowerStateMap[[int]$DeviceStatus.PowerState]

Output:

17
IsPublic IsSerial Name                                     BaseType
-------- -------- ----                                     --------
True     True     Int64                                    System.ValueType
"Testing Without Casting"
"Testing with casting"
On

Upvotes: 2

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