Format-Query.ps1

function Format-Query(
    [Parameter(Mandatory)]
    [hashtable]
    $Table
) {
    <#
        .SYNOPSIS
        Format URI query
        .DESCRIPTION
        Take a hashtable and format as a URI query string
    #>
    $Query = @()
    $Table.GetEnumerator() | ForEach-Object {
        $Query += ($_.Key + "=" + $_.Value)
    }
    return $Query | Join-String -Property $_ -Separator "&" -OutputPrefix "?"
}

Example:

Format-Query -Table @{
    Name = "Richard"
    Type = "Person"
}

Output:

?Name=Richard&Type=Person