# Input and Decisions

Give a script parameters, ask a question, and make it choose with if and switch.

Updated: November 10, 2026

## [Input](https://www.ask-codey.com/courses/powershell-in-depth/topics/powershell-input)

1. [Parameters: \`param()\`](https://www.ask-codey.com/lessons/powershell-param) (Apprentice): A param() block at the top of a script names its inputs, so one script works on any folder; each parameter can have a type, a default value or be a \[switch\], Mandatory makes PowerShell ask for a missing one, and Tab completes their names.
2. [Asking Questions: \`Read-Host\`](https://www.ask-codey.com/lessons/powershell-read-host) (Apprentice): Read-Host asks a question, waits, and hands back what was typed, always as text, -MaskInput shows stars instead of the answer, and a parameter is usually the better way in, because a question needs someone at the keyboard and a script that runs on its own has no one there.

## [Decisions](https://www.ask-codey.com/courses/powershell-in-depth/topics/powershell-decisions)

1. [If This, Then That: \`if\`, \`elseif\` and \`else\`](https://www.ask-codey.com/lessons/powershell-if-statements) (Apprentice): if runs a block of commands only when its test is True, elseif adds another test, else catches everything left, -and, -or and -not join tests together, and exit stops a script early, so a backup copies only when something changed and explains itself when it can't.
2. [Many Choices: \`switch\`](https://www.ask-codey.com/lessons/powershell-switch) (Apprentice): switch compares one value with a list of choices and runs the block of each one that matches, with default for anything else; -Wildcard and -Regex match patterns instead of exact text, and a switch on a Read-Host answer makes a simple menu.

## [Exercise: The Smart Backup](https://www.ask-codey.com/courses/powershell-in-depth/topics/exercise-powershell-the-smart-backup)

1. [Exercise: The Smart Backup](https://www.ask-codey.com/lessons/exercise-powershell-the-smart-backup) (Apprentice): Finish a backup script that copies a file only when it's needed, with parameters, a usage line, -List and a -Menu, checks for missing, folder and empty names, and a switch that says what kind of file it copied, while a Pester check runs it job by job.

Source: https://www.ask-codey.com/courses/powershell-in-depth/chapters/powershell-input-and-decisions