Performance: -join slower than [string]::Join() #10377
Description
Steps to reproduce
Joining 100kb random numbers, the operator is much slower, ~13x here:
[string[]]$nums = Get-Random -Minimum 1 -Maximum 100 -Count 100kb
measure-command { $nums -join ',' } |% TotalMilliseconds
measure-command { [string]::join(',', $nums) } |% TotalMilliseconds
234.82690000000002
14.497100000000001Stranger, with a big wordlist text file, loading it two different ways seems to make a difference:
$w1 = Get-Content d:\test\wordlist.txt; $w1.Count
$w2 = ${D:\test\wordlist.txt}; $w2.Count
measure-command { $w1 -join "`r`n" } |% TotalMilliseconds
measure-command { $w2 -join "`r`n" } |% TotalMilliseconds
measure-command { [string]::join("`r`n", $w1) } |% TotalMilliseconds
measure-command { [string]::join("`r`n", $w2) } |% TotalMilliseconds
172823
172823 # same word count
254.6534
423.63100000000003 # <-- slower?
183.01510000000002
16.148400000000002 # <-- how come this one is SO fast?Environment data
PS D:\> $PSVersionTable
Name Value
---- -----
PSVersion 7.0.0-preview.1
PSEdition Core
GitCommitId 7.0.0-preview.1
OS Microsoft Windows 10.0.17763
Platform Win32NT
PSCompatibleVersions {1.0, 2.0, 3.0, 4.0…}
PSRemotingProtocolVersion 2.3
SerializationVersion 1.1.0.1
WSManStackVersion 3.0