Comma quibbling is a task originally set by Eric Lippert in his blog.



Task

Write a function to generate a string output which is the concatenation of input words from a list/sequence where:

 An input of no words produces the output string of just the two brace characters "{}".
 An input of just one word, e.g. ["ABC"], produces the output string of the word inside the two braces, e.g. "{ABC}".
 An input of two words, e.g. ["ABC", "DEF"], produces the output string of the two words inside the two braces with the words separated by the string " and ", e.g. "{ABC and DEF}".
 An input of three or more words, e.g. ["ABC", "DEF", "G", "H"], produces the output string of all but the last word separated by ", " with the last word separated by " and " and all within braces; e.g. "{ABC, DEF, G and H}".


Test your function with the following series of inputs showing your output here on this page:

 [] # (No input words).
 ["ABC"]
 ["ABC", "DEF"]
 ["ABC", "DEF", "G", "H"]


Note: Assume words are non-empty strings of uppercase characters for this task.




 
function Out-Quibble
{
    [OutputType([string])]
    Param
    (
        # Zero or more strings.
        [Parameter(Mandatory=$false, Position=0)]
        [AllowEmptyString()]
        [string[]]
        $Text = ""
    )
 
    # If not null or empty...
    if ($Text)
    {
        # Remove empty strings from the array.
        $text = "$Text".Split(" ", [StringSplitOptions]::RemoveEmptyEntries)
    }
    else
    {
        return "{}"
    }
 
    # Build a format string.
    $outStr = ""
    for ($i = 0; $i -lt $text.Count; $i++)
    { 
        $outStr += "{$i}, "
    }
    $outStr = $outStr.TrimEnd(", ")
 
    # If more than one word, insert " and" at last comma position.
    if ($text.Count -gt 1)
    {
        $cIndex = $outStr.LastIndexOf(",")
        $outStr = $outStr.Remove($cIndex,1).Insert($cIndex," and")
    }
 
    # Output the formatted string.
    "{" + $outStr -f $text + "}"
}
 