将字符串值“$ false”转换为布尔变量

Question

Reason I'm Doing This

I'm trying to set a token in a file I have. The contents of the token is 1 line in the file, and it's string value is $token=$false

Simplified to test code

When I try to convert this token into a bool value, I'm having some problems. So I wrote test code and found I'm not able to convert the string to a bool value.

[String]$strValue = "$false"
[Bool]$boolValue = $strValue

Write-Host '$boolValue =' $boolValue

This gives the following error...

Cannot convert value "System.String" to type "System.Boolean", parameters of this type only accept booleans or numbers, use $true, $false, 1 or 0 instead.
At :line:2 char:17
+   [Bool]$boolValue <<<<  = $strValue

As you can see, I am using the $false value as is suggested by the error message, but it's not accepting it. Any ideas?

Answer 1

In PowerShell, the usual escape character is the backtick. Normal strings are interpolated: the $ symbol is understood and parsed by PowerShell. You need to escape the $ to prevent interpolation. This should work for you:

[String]$strValue = "`$false"

To convert "$true" or "$false" to a boolean in a generic way, you must first drop the leading $ :

$strValue = $strValue.Substring(1)

Then convert to boolean:

[Boolean]$boolValue = [System.Convert]::ToBoolean($strValue)

Using your code from your comment, the shortest solution would be:

$AD_Export_TokenFromConfigFile =
   [System.Convert]::ToBoolean(Get-Content $AD_Export_ConfigFile
                               | % {
                                      If($_ -match "SearchUsersInfoInAD_ConfigToken=") {
                                          ($_ -replace '*SearchUsersInfoInAD_ConfigToken*=','').Trim()
                                      }
                                   }.Substring(1))