powershell - Why is the value of "switch" type parameter passed to a string parameter? -


the test code (test.ps1):

param(     [string]$content = $null,     [switch]$flag = $false ) write-host $content

output:

 ps c:\users\powershell> .\test.ps1  ps c:\users\powershell> .\test.ps1 -flag $true     true ps c:\users\powershell> .\test.ps1 -flag $false false ps c:\users\powershell> .\test.ps1 -flag $true -content "lalala" lalala

no matter set $content $null, or "", or without default value, output same.

so why $content take value $flag?

@petseral indicated misunderstanding is, maybe bit brief, i'll elaborate little more.

a [switch] parameter doesn't take value regular parameters. set true or false respectively providing or omitting parameter:

 ps c:\> get-content .\test.ps1 param(     [string]$content = $null,     [switch]$flag ) $flag.ispresent $content ps c:\> .\test.ps1 false  ps c:\> .\test.ps1 -flag true

alternatively can explicitly pass value putting colon between switch parameter , value:

 ps c:\> .\test.ps1 -flag:$false false  ps c:\> .\test.ps1 -flag:$true true

whitespace after colon allowed, not before (-flag: $false passes $false switch value, -flag :$false doesn't).

if try assign switch value without colon value passed next parameter in line, in case -content parameter:

 ps c:\> .\test.ps1 -flag $false true         # value of parameter $flag false        # value of (positional) parameter $content ps c:\> .\test.ps1 -flag -content $false true         # value of parameter $flag false        # value of (named) parameter $content

if use -flag $true (without colon) and pass value (named) parameter -content value $true passed unnamed third parameter (accessible via automatic variable $args), same if put value @ end of statement:

 ps c:\> get-content .\test2.ps1 param(     [string]$content = $null,     [switch]$flag ) $flag.ispresent $content $args[0] ps c:\> .\test2.ps1 -flag $false -content 'something' true false        # $false passed unnamed 3rd parameter ps c:\> .\test2.ps1 -flag:$false -content 'something' false        # $false passed explicit value of switch parameter $flag ps c:\> .\test2.ps1 -flag -content 'something' $false true false        # $false passed unnamed 3rd parameter

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