[PowerShell每日技巧]4.0中的隐藏技巧：数组扩展(20140120)

DAIC

PowerShell 4.0 (final version as found in Windows 8.1) has Foreach and Where built directly into arrays. This is a geek stuff, so there is no apparent advantage to it over using the traditional pipeline (except maybe for speed).

This line will get only uneven numbers from a list of numbers:

1. @(1..10).Where({$_ % 2})

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And this line will get only services that are actually running:

1. @(Get-Service).Where({$_.Status -eq 'Running'})

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And there is more (undocumented) stuff. This line will get all numbers that are greater than 2, but only the first 4 of them:

1. @(1..10).Where({$_ -gt 2}, 'skipuntil', 4)

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Finally, this line will do the same, but then converts them to the TimeSpan objects:

1. @(1..10).Where({$_ -gt 2}, 'skipuntil', 5).Foreach([Timespan])

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http://powershell.com/cs/blogs/tips/archive/2014/01/20/hidden-array-extensions-in-powershell-4-0.aspx