stringtest.ps1

#! /usr/bin/pwsh

# Consider these variations on coding this series of
# string concatenations

$count=10000

# get our 'native' end of line
$eol=@'


'@

"eol is `"$eol`""

'$s = $s + "xyzzy" + "`n"'
$s = ""
"$(Measure-Command {1..$count | ForEach-Object {$s = $s + "xyzzy" + "`n"} } | Select-Object -exp ticks)`t$($s.length)"

'$s = $s + ("xyzzy" + "`n")'
$s = ""
"$(Measure-Command {1..$count | ForEach-Object {$s = $s + ("xyzzy" + "`n")} } | Select-Object -exp ticks)`t$($s.length)"

'$s = $s + "xyzzy`n"'
$s = ""
"$(Measure-Command {1..$count | ForEach-Object {$s = $s + "xyzzy`n"} } | Select-Object -exp ticks)`t$($s.length)"

'$s = $s + "xyzzy`n"'
$s = ""
"$(Measure-Command {1..$count | ForEach-Object {$s = $s + "xyzzy`n"} } | Select-Object -exp ticks)`t$($s.length)"

'$s += "xyzzy" + "`n"'
$s = ""
"$(Measure-Command {1..$count | ForEach-Object {$s += "xyzzy" + "`n"} } | Select-Object -exp ticks)`t$($s.length)"

# String formatting is faster than doing multiple concatenations if you can do multiple at once:
'$s += "{0}{1}" -f "xyzzy", "`n"'
$s = ""
"$(Measure-Command {1..$count | ForEach-Object {$s += "{0}{1}" -f "xyzzy", "`n"} } | Select-Object -exp ticks)`t$($s.length)"

# arrays are even worse
'$sarray += "xyzzy`n"'
$s = ""
$sarray = @("")
Measure-Command {
    1..$count | ForEach-Object {$sarray += "xyzzy`n"}
    $s=$sarray -Join ""
} | Select-Object -exp ticks
$s.length

#use StringBuilder.
'$s.Append("xyzzy"); $s.Append("`n")'
$s = New-Object Text.StringBuilder
Measure-Command {1..$count | ForEach-Object {$s.Append("xyzzy"); $s.Append("`n")} } |
Select-Object -exp ticks
$s.length

'$s.Append("xyzzy" + "`n")'
$s = New-Object Text.StringBuilder
Measure-Command {1..$count | ForEach-Object {$s.Append("xyzzy" + "`n")} } |
Select-Object -exp ticks
$s.length

'$s.Append("xyzzy`n")'
$s = New-Object Text.StringBuilder
Measure-Command {1..$count | ForEach-Object {$s.Append("xyzzy`n")} } |
Select-Object -exp ticks
$s.length

# @''@ used to include native newline.
'$s.Append(@)'
$s = New-Object Text.StringBuilder
Measure-Command {1..$count | ForEach-Object {$s.Append(@'
xyzzy

'@
)} } |
Select-Object -exp ticks
$s.length

'$list.Add("xyzzy`n")'
Measure-Command {
    $list = New-Object System.Collections.Generic.List[System.String]
    for ($i = 0; $i -lt $count; $i++)
    {
        $list.Add("xyzzy`n")
    }
    $s = $list.ToArray() -Join ""
} |
Select-Object -exp ticks
$s.length