Function that checks and validates its parameters

check_parameters.ps1

Function Foo
{ 
    Param( 
        [ValidateSet("Tom","Dick","Jane")] 
        [String]$Name, 
        
        [ValidateRange(21,65)] 
        [Int]$Age, 

        [ValidateScript({Test-Path $_ -PathType 'Container'})] 
        [string]$Path
    ) 
    
    # Do something
}