Instantly share code, notes, and snippets.

# thedavecarroll/1-Intermediate.ps1

Last active February 16, 2021 00:27
Show Gist options
• Save thedavecarroll/ccece8563e9fe995ef8c760c2d3c6abe to your computer and use it in GitHub Desktop.
Another PowerShell Math Challenge - IronScripter Challenge - 2021-02-09 (Intermediate Only)
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters. Learn more about bidirectional Unicode characters
 #requires -Version 7 function Get-SumTotal { [CmdLetBinding()] param( [Parameter(Mandatory,Position = 0,ValueFromPipeline)] [ValidatePattern('^\d{1,10}\$', ErrorMessage = '"{0}" does not match only numbers 0-9 with a maximum of 10.')] #[ValidatePattern('^\d{1,10}\$')] #[ValidateScript({ if (\$_ -notmatch '^\d{1,10}\$') { throw ('{0}"{1}" does not match only numbers 0-9 with a maximum of 10.' -f [System.Environment]::NewLine,\$_) } else { \$true }})] [string]\$Value, [switch]\$Full ) process { \$NumberList = [System.Collections.ArrayList]::new() \$Value.ToCharArray() | ForEach-Object { [void]\$NumberList.Add([System.Char]::GetNumericValue(\$_)) } \$SumTotal = \$NumberList | Measure-Object -Sum \$Calculation = '{0} = {1}' -f (\$NumberList -join ' + '),\$SumTotal.Sum \$SumTotalOutput = [PsCustomObject]@{ Value = \$Value NumberCount = \$SumTotal.Count Sum = \$SumTotal.Sum Calculation = \$Calculation } \$Calculation | Write-Verbose if (\$PSBoundParameters.ContainsKey('Full')) { \$SumTotalOutput } else { \$SumTotalOutput.Sum } } }

# Examples

## Intermediate

```PS7.1.1 > 1234567890 | Get-SumTotal
PS7.1.1 > 12345678902 | Get-SumTotal
PS7.1.1 > 123456789 | Get-SumTotal -Verbose
PS7.1.1 > 123456789 | Get-SumTotal -Verbose -Full
PS7.1.1 > 'G123456789' | Get-SumTotal```
```# 1st run
45

# 2nd run
Get-SumTotal: Cannot validate argument on parameter 'Value'. "12345678902" does not match only numbers 0-9 with a maximum of 10.

# 3rd run
VERBOSE: 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 = 45
45

# 4th run
VERBOSE: 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 = 45

Value     NumberCount Sum Calculation
-----     ----------- --- -----------
123456789           9  45 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 = 45

# 5th run
Get-SumTotal: Cannot validate argument on parameter 'Value'. "G123456789" does not match only numbers 0-9 with a maximum of 10.```

### thedavecarroll commented Feb 11, 2021

There are 2 `Validate*` attributes that have been commented out.

The `ValidatePattern` attribute, prior to PowerShell Core, displays a generic, hard-to-read error message. The commented out attribute shows how to validate in Windows PowerShell 5.1. The other, uncommented, shows how to validate with PowerShell Core (6.x) and PowerShell (7.x).

The commented `ValidateScript` shows one way to provide the user with a more specific error message. This requires more code than the targeted validate attributes and can support more complex validation rules. I could have easily stayed with this attribute, but I chose to go with PowerShell 7 hence the `#Requires` statement.