PowerShell - Using Parameter Sets

💡 What are parameter sets in PowerShell and how to use them

Have you ever wondered when you are writing a PowerShell function or commandlet how you can make only certain parameters be presented to the consumer of the function in certain scenarios? That's where parameter sets come in. 😄

We will look at the following test function: [Test-ParameterSets] on exactly how this functionality can be used.

The first step is to add a DefaultParameterSetName="Default". We can set that in our [CmdletBinding()] as follow:



// code/demo-function.ps1#L2-L2

[CmdletBinding(SupportsShouldProcess, DefaultParameterSetName="Default")]

By declaring a default parameter set name on our [CmdletBinding()] will set all of our parameters defined under the Default set. What we will do next is define which parameters needs to be presented if the parameter switch $A is used. We do not want to present parameters from switch $B in this case. We will do this by defining a new parameter set name and grouping the parameters we want to be part of that particular set.



// code/demo-function.ps1#L8-L13

[Parameter(Mandatory=$false, ParameterSetName="A")]
[Switch]$A,
[Parameter(Mandatory=$false, ParameterSetName="A")]
[string]$AParameter1,
[Parameter(Mandatory=$false, ParameterSetName="A")]
[string]$AParameter2,

We will also give parameter switch $B and it's corresponding parameters, it's own parameter set name.



// code/demo-function.ps1#L14-L19

[Parameter(Mandatory=$false, ParameterSetName="B")]
[Switch]$B,
[Parameter(Mandatory=$false, ParameterSetName="B")]
[string]$BParameter1,
[Parameter(Mandatory=$false, ParameterSetName="B")]
[string]$BParameter2

Now that we have defined our parameter sets and grouped the relevant parameters according to their sets our function/Cmdlet will now only present corresponding parameters based on which switch is used when calling the function/Cmdlet.