A PowerShell ordered array is usually an ordered hashtable: put [ordered] in front of @{} and the keys stay in the order you typed them. Plain arrays already keep their order, so they don’t need anything extra: Below, I’ll add, insert, read and sort entries, then cover the collections that keep items sorted. I tested … Read more
The short version of Where-Object vs Select-Object: Where-Object decides which objects (rows) stay in the pipeline, and Select-Object decides which properties (columns) each object keeps. Most real commands use both, filter first: I’ll show what each cmdlet returns, why the order matters, the row tricks Select-Object also has, and one version difference between PowerShell 7 … Read more
To expand an array in PowerShell, pipe the objects to Select-Object -ExpandProperty and name the property that holds the array. You get every value as its own item instead of a {a, b} blob: Below I cover dot notation, keeping the parent value, the {a, b, c…} display limit, flattening nested arrays and growing an … Read more
To convert a UTF-8 file to ANSI in PowerShell 7.4 or later, read it as UTF-8 and write it back with -Encoding ansi: Windows PowerShell 5.1 has no ansi value and uses -Encoding Default instead, which means something completely different in PowerShell 7. Below I check the real bytes in both versions and show a … Read more
To reverse an array in PowerShell, pass it to the .NET [array]::Reverse() method. It flips the items in place, so the same variable now holds them in the opposite order: To keep the original order too, a negative index range gives you a reversed copy. I ran each method in PowerShell 7 and 5.1. Reverse … Read more
The quickest way to clear an array in PowerShell is to assign it a new empty array with @(). The variable then holds zero items: That isn’t the only option, and the obvious one, $cities.Clear(), doesn’t do what most people expect. I tested each method in PowerShell 7 and 5.1, and one works only in … Read more
To remove blank lines from an array in PowerShell, pipe the array to Where-Object and keep only items that aren’t null, empty or whitespace: I tested every example below in PowerShell 7 and Windows PowerShell 5.1, including a popular shortcut that crashes on null items. Remove blank lines from an array with Where-Object This array … Read more
PowerShell has no built-in chunk cmdlet, so to split an array into smaller arrays you step through it with a for loop and slice each piece with a range. The comma keeps every chunk as its own array: I’ll also wrap it in a function, show the one-chunk trap, and cover LINQ Chunk, a set … Read more
To print an array in PowerShell, type the variable name or pass it to Write-Output, and every item prints on its own line. For a single line, join the items with -join: That covers most cases, but arrays of objects, hashtables and files behave differently. I ran each example below in PowerShell 7 and Windows … Read more
To find invalid characters in a string in PowerShell, compare it against the characters Windows doesn’t allow. For file names, IndexOfAny with GetInvalidFileNameChars returns the position of the first bad one, or -1 if the name is clean: “Invalid” depends on where the text is going, though. Below I check file names, list every bad … Read more