# Variables: \`$name\` A variable is a name PowerShell keeps a value under, so $owl = "…" stores a long path once, $drawings = Get-ChildItem … keeps a whole list of files, and $owl hands the value back in any later command until you close the window. Apprentice · PowerShell · Updated November 10, 2026 ## After this lesson you can - Store a value or a command's answer in a variable with $name = …, and use it in later commands - Explain what a variable holds once it's set, a snapshot that changes only when you set it again, and why a mistyped name gives nothing ## Key takeaways - `$owl = '…'` puts a value in a box called owl. `$owl`, read "the value of owl", hands it back in any later command. - A variable can hold a command's whole answer: `$drawings = Get-ChildItem …` keeps the file objects, properties and all. - A variable is a snapshot: it doesn't change when the folder does, until you set it again. - Names ignore capital letters. A name you never set is empty, not an error, so a typo quietly gives you nothing. - Your variables last until you close the window. `$HOME` and `$PSVersionTable` are PowerShell's own, filled in for you. You're working in a folder five levels deep, and you've typed its path so often your fingers know it, typos included. Or you listed a folder's files, and now you want to sort that same list a second way without asking for it again. Or a guide says "save the result of this command, you'll need it in a minute." Each time, you want PowerShell to remember something for you. That's what a **variable** is for, and every script in this course is built on them. A help-desk tech keeps a computer's name in one while fixing it; a web developer keeps a project's folder in one. ## Set up the workshop This chapter's practice folder is a workshop. Ada Wren, an inventor, keeps her machines there (they're tiny PowerShell scripts), and her newest project, a clockwork owl, sits four folders deep. Copy these lines into PowerShell. They print nothing when they work, and running them again is safe: ```powershell New-Item -ItemType Directory -Force -Path "$HOME\terminal-practice\workshop\tools", "$HOME\terminal-practice\workshop\projects\clockwork-owl\drawings" | Out-Null Set-Location "$HOME\terminal-practice\workshop" Set-Content letter.txt 'Back from the inventors'' fair on December 4. Keep the machines running! - Ada' Set-Content kettle-bot.ps1 'if ($env:POWER -eq "on") { "Pouring tea..." } else { "NO POWER" }' Set-Content tools\oil.ps1 '"Glug, glug. The gears are oiled and shining."' Set-Content projects\clockwork-owl\drawings\wings.txt 'Wings: 12 brass feathers each, hinged at the shoulder' Set-Content projects\clockwork-owl\drawings\beak.txt 'Beak: copper, opens on the hour' Set-Content projects\clockwork-owl\drawings\gears.txt 'Gears: 7 teeth on the small one, 21 on the big one, 3 turns to 1' ``` ## A name for a value: \`$owl = …\` Picture a box with a label on it. The label is the variable's name, and what you put inside is its **value**. In PowerShell every variable's name starts with `$`, and `=` puts a value in the box: ```powershell $owl = "$HOME\terminal-practice\workshop\projects\clockwork-owl" $owl ``` ```text C:\Users\Sam\terminal-practice\workshop\projects\clockwork-owl ``` Read the first line as "put this path in the box called owl". It printed nothing: PowerShell quietly kept the value. The second line is the variable on its own, and `$owl` is read "the value of owl", so PowerShell shows what's in the box. (The double quotes let `$HOME` fill in your home folder; the next lesson, *Text: Quotes and $( )*, shows how.) Now `$owl` works anywhere you'd type the path. `Set-Location $owl` takes you there, and this lists the owl's drawings: ```powershell Get-ChildItem "$owl\drawings" ``` ```text Directory: C:\Users\Sam\terminal-practice\workshop\projects\clockwork-owl\drawings Mode LastWriteTime Length Name ---- ------------- ------ ---- -a--- 11/7/2026 10:15 AM 33 beak.txt -a--- 11/7/2026 10:15 AM 66 gears.txt -a--- 11/7/2026 10:15 AM 55 wings.txt ``` Your dates and times will be the moment you made the practice folder. ## A whole answer in a box A variable can hold a command's answer too. Here the box holds the three file objects themselves, with every property from *What an Object Is: Get-Member*, so you can count them and sort them without asking the disk again: ```powershell $drawings = Get-ChildItem "$owl\drawings" $drawings.Count $drawings | Sort-Object Length -Descending | Select-Object Name, Length ``` ```text 3 Name Length ---- ------ gears.txt 66 wings.txt 55 beak.txt 33 ``` A variable is a photo, not a window. Add a drawing to the folder, and the box still holds the three files it got: ```powershell Set-Content "$owl\drawings\tail.txt" 'Tail: 9 brass feathers, fanned' $drawings.Count $drawings = Get-ChildItem "$owl\drawings" $drawings.Count ``` ```text 3 4 ``` Only when you set the variable again does it see the fourth file. Setting a variable replaces what was in the box; `+=`, read "add to", adds to what's there. `$cups = 0`, then `$cups += 1` twice, leaves `2` in `$cups`. ## Names and typos Names ignore capital letters: `$OWL` and `$owl` are the same box. Use letters, digits and underscores; a dash looks like the start of a parameter, so PowerShell stops: ```powershell $gear-size = 7 ``` ```text ParserError: Line | 1 | $gear-size = 7 | ~~~~~ | Unexpected token '-size' in expression or statement. ``` `$gearSize`, with a capital letter where each new word starts, is the usual way to write a name of two words. A mistyped name is a quieter problem. A box you never filled is empty, so `$owel` prints nothing at all, with no error to warn you. When a command does something strange, check your variable's spelling first. ## PowerShell's own variables Some boxes are filled before you type anything. `$HOME` is your home folder, `$PSVersionTable` says which PowerShell you're running, and `$_` is "this item" from *Filtering: Where-Object and Comparisons*. They're **automatic variables**, so don't use their names for your own. `Get-Variable` shows a box's name and its value, without the `$`: ```powershell Get-Variable owl ``` ```text Name Value ---- ----- owl C:\Users\Sam\terminal-practice\workshop\projects\clockwork-owl ``` Your own variables last until you close the window. A new window starts with empty boxes; *Your Profile*, in the next chapter, shows how to fill some every time PowerShell starts. Everything here works the same in Windows PowerShell 5.1 and on a Mac or Linux, where paths use `/`. **Try it.** Put your Downloads folder in a variable with `$dl = "$HOME\Downloads"`, then count the files in it with `(Get-ChildItem $dl -File).Count`. ## Check yourself 2 questions to try on the lesson page. ## So what A variable lets PowerShell remember for you: a path you'd rather not retype, or a whole command's answer to sort and count again and again. Scripts are built from them, starting in this chapter. ## Key terms - [Variable ($)](https://www.ask-codey.com/glossary/variable-powershell) - [Automatic Variable](https://www.ask-codey.com/glossary/automatic-variable) ## Cheat sheets - [Variables: \`$name\`](https://www.ask-codey.com/cheat-sheets/powershell-variables-cheat-sheet) ## Related - [Text: Quotes and \`$( )\`](https://www.ask-codey.com/lessons/powershell-strings) - [Lists and Lookups: Arrays and Hashtables](https://www.ask-codey.com/lessons/powershell-arrays-and-hashtables) - [Environment Variables and \`PATH\`](https://www.ask-codey.com/lessons/powershell-environment-variables) - [JSON: ConvertFrom-Json and ConvertTo-Json](https://www.ask-codey.com/lessons/powershell-json) Source: https://www.ask-codey.com/lessons/powershell-variables