There was a Reddit post recently that gave me an opportunity to try something I’m not sure I’ve tried before: nested switch statements—-switch statements inside switch statements. So we’re on the same page, I’ve written an example of a basic, non-nested switch. It provides some of the same functionality as an If-ElseIf. I’ll typically use a switch statement instead of an If-ElseIf when there’s three or more outcomes. It’s easier to read, and it looks cleaner.
In the example below, a specific phrase will be written if the value in the $Fruit variable is apple, banana, or pear. If it’s not one of those, it’ll take the default action. In the case below, the default action indicates that an apple, banana, or pear wasn’t chosen. Switch statements will sometimes be called case statements in other languages.
$Fruit = 'banana'
Switch ($Fruit) {
'apple' {'You chose apple.'; break}
'banana' {'You chose banana.'; break}
'pear' {'You chose pear.'; break}
default {'You didn''t choose an apple, banana, or pear.'}
}
As a part of my nested switch statement testing, I wrote this example using automobile makes and models. The outermost switch statement makes a determination of which nested switch statement to execute.
$Make = 'Ford'
$Model = 'Escape'
Switch ($Make) {
'Ford' {
Switch ($Model) {
'Mustang' {Write-Output -InputObject 'You selected the Ford Mustang.'; break}
'Escape' {Write-Output -InputObject 'You selected the Ford Escape.'; break}
default {Write-Output -InputObject "You selected Ford, however, the $Model isn't a valid model for this make."; break}
}
}
'Chevy' {
Switch ($Model) {
'Corvette' {Write-Output -InputObject 'You selected the Chevy Corvette.'; break}
'Camaro' {Write-Output -InputObject 'You selected the Chevy Camaro.'; break}
default {Write-Output -InputObject "You selected Chevy, however, the $Model isn't a valid model for this make."; break}
}
}
'Dodge' {
Switch ($Model) {
'Charger' {Write-Output -InputObject 'You selected the Dodge Charger.'; break}
'Viper' {Write-Output -InputObject 'You selected the Dodge Viper.'; break}
default {Write-Output -InputObject "You selected Dodge, however, the $Model isn't a valid model for this make."; break}
}
}
}
Should we take this further—-a switch statement inside a switch statement inside a switch statement? I’m not going to lie, it started to get confusing and so my first recommendation would be to try and steer clear of the multi-nesting this deep (3 levels). I’ve removed some of the example above—-Chevy and Dodge—-in my example below and focused on the Ford (pun, absolutely intended). To help, I’ve included comments on the closing brackets. This multi-nested switch statement will return different values based on the make, the model, and the year, too.
$Make = 'Ford'
$Model = 'Escape'
$Year = '2016'
Switch ($Make) {
'Ford' {
Switch ($Model) {
'Mustang' {
Switch ($Year) {
'2015' {Write-Output -InputObject "You selected the 2015 Ford Mustang."; break}
'2016' {Write-Output -InputObject "You selected the 2016 Ford Mustang"; break}
default {Write-Output -InputObject "You selected the Ford Mustang with a non-matching year."; break}
} # End Mustang Year Switch.
} # End Mustang Switch.
'Escape' {
Switch ($Year) {
'2015' {Write-Output -InputObject "You selected the 2015 Ford Escape."; break}
'2016' {Write-Output -InputObject "You selected the 2016 Ford Escape."; break}
default {Write-Output -InputObject "You selected the Ford Escape with a non-matching year."; break}
} # End Escape Year Switch.
} # End Escape Switch.
default {Write-Output -InputObject "You selected a Ford; however, the $Model isn't a valid model for this make."}
} # End Ford Model Switch.
} # End Ford Switch.
default {Write-Output -InputObject 'Sorry, we''re only dealing with Fords (at the moment).'}
} # End Make Switch.
So I can track it down later, here’s the post I read on Reddit that influenced this post. It includes the link to my possible, partial solution; however, that direct link is here: http://pastebin.com/KRxRb1VM.
Update: It has occurred to me that it might be easier to follow this thrice nested switch without all the comments. I’ve removed those below.
$Make = 'Ford'
$Model = 'Escape'
$Year = '2016'
Switch ($Make) {
'Ford' {
Switch ($Model) {
'Mustang' {
Switch ($Year) {
'2015' {Write-Output -InputObject "You selected the 2015 Ford Mustang."; break}
'2016' {Write-Output -InputObject "You selected the 2016 Ford Mustang"; break}
default {Write-Output -InputObject "You selected the Ford Mustang with a non-matching year."; break}
}
}
'Escape' {
Switch ($Year) {
'2015' {Write-Output -InputObject "You selected the 2015 Ford Escape."; break}
'2016' {Write-Output -InputObject "You selected the 2016 Ford Escape."; break}
default {Write-Output -InputObject "You selected the Ford Escape with a non-matching year."; break}
}
}
default {Write-Output -InputObject "You selected a Ford; however, the $Model isn't a valid model for this make."}
}
}
default {Write-Output -InputObject 'Sorry, we''re only dealing with Fords (at the moment).'}
}
