Bijay Kumar 
To import an Excel file in PowerShell, install the ImportExcel module and run Import-Excel. It reads the first worksheet into an array, one object per row, with the header row as property names: If Excel is installed and you’d rather skip the module, the Excel COM object gives you a two-dimensional array through UsedRange.Value2. I … 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 replace a value in a PowerShell array, assign to its index: $array[1] = ‘new value’. To replace text in every item at once, use -replace on the whole array: Output: Index assignment changes the array in place. The rest of this guide covers replacing across all items, replacing whole items only, and a few … Read more
To pick random items from an array in PowerShell, pipe the array to Get-Random. Add -Count to get several different items at once: That covers most scripts. Below I’ll show repeats, shuffling, repeatable picks, weighted choices, and the places where Windows PowerShell 5.1 behaves differently from PowerShell 7. How do I pick a random item … Read more
The fastest way to find duplicates in an array in PowerShell is Group-Object: it groups equal values, and any group with a Count above 1 is a duplicate: I’ll also count each value, make the check case-sensitive, find duplicate positions and duplicate objects, and show why Group-Object crawls in Windows PowerShell 5.1 and what to … 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
To create a character array in PowerShell, call ToCharArray() on a string. It returns a Char[] array with one item for each character, which you can loop through, filter or count: Output: Below I compare the other ways to build one, then cover letter ranges, filtering, counting and joining characters back into a string. Every … 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