Getting Started with PowerShell

A beginner-friendly, production-quality PowerShell course that teaches the fundamentals through progressive lessons, reusable functions, and automated tests.

Course Overview

This course is designed for people who are new to PowerShell and want hands-on practice. Each lesson introduces a focused set of concepts, includes heavily commented examples, defines testable functions, and ends with follow-along exercises.

Learning Objectives

By the end of this course, you will be able to:

• Run PowerShell scripts and commands confidently
• Work with variables, strings, and core data types
• Use operators, conditionals, and loops
• Manipulate arrays and hashtables
• Write reusable functions with parameters and return values
• Build advanced functions that accept pipeline input
• Handle errors predictably with try/catch/finally
• Read and write CSV, JSON, and text files
• Validate your work with Pester and PSScriptAnalyzer

Prerequisites

• PowerShell 7 or later
• A code editor such as Visual Studio Code
• Recommended: the PowerShell extension for VS Code

Install Pester and PSScriptAnalyzer

Open PowerShell and run:

Install-Module Pester -Scope CurrentUser -Force -SkipPublisherCheck
Install-Module PSScriptAnalyzer -Scope CurrentUser -Force

If prompted to trust the PSGallery repository, answer Yes.

Directory Structure

powershell-beginners/
├── README.md
├── PSScriptAnalyzerSettings.psd1
├── lint.ps1
├── run-tests.ps1
├── lessons/
└── tests/

Running a Lesson

From the project folder:

cd ~/powershell-beginners
pwsh ./lessons/01-hello-world.ps1

You can also dot-source a lesson to load its functions into your current session:

. ./lessons/01-hello-world.ps1
Get-Greeting -Name 'Ada'

Running the Test Suite

pwsh ./run-tests.ps1

Running the Linter

pwsh ./lint.ps1

CI and Documentation Automation

CI keeps separate PSScriptAnalyzer and Pester jobs, with tests running after lint succeeds. CI uses the central PSScriptAnalyzer workflow, pinned to an exact module version, and analyzes PowerShell sources under the repository root using PSScriptAnalyzerSettings.psd1; it fails on Error and Warning diagnostics. The local lint.ps1 helper uses the same settings and diagnostic threshold for lessons/ and tests/. Pester 5 or later writes NUnit XML to test-results.xml, uploaded as pester-test-results even when tests fail.

Automation validation comes from DevOpsDerek/workflows at commit dac4b81c298cb3ea6821ea312efa5375f42d5ccb. The catalog's checked-script helper does not support PowerShell, so it does not replace this course's test or lint implementation. The central validator lints Actions configuration and, when gh-aw sources exist, compiles them and checks committed locks for drift. It is independent of the existing lint-to-test dependency. This repository currently has no gh-aw sources or locks.

Manual course documentation upkeep is deferred. The current gh-aw compiler (v0.89.21) hardcodes persisted write-capable checkout credentials in the PR safe-output job and has no supported override. The documentation agent source and generated lock have been removed rather than hand-editing a lock or introducing an insecure workaround.

Reconsider this capability only after the central compiler supports persist-credentials: false for the write job and credential handling is verified in regenerated output. Any future adoption must pin the central API, restrict proposals to bounded documentation-only draft PRs, preserve course examples without executing lesson scripts, and require human review and manual merge. No agent secret or PR-write setting is needed for the validator-only adoption; no automated merge, release, deployment, or publishing is enabled.

Lesson Summary

#	Title	Key Concepts
01	Hello World & Variables	Write-Output, Write-Host, variables, interpolation, comments
02	Data Types	strings, numbers, booleans, datetimes, casting
03	Operators	arithmetic, comparison, logical, regex, replace
04	Conditionals	if/elseif/else, switch, nested checks
05	Loops	for, foreach, while, do/while, break, continue, pipeline processing
06	Collections	arrays, indexing, count, hashtables, ArrayList
07	Functions Basics	parameters, return values, defaults, scope
08	Functions Advanced	CmdletBinding, validation, pipeline input, Begin/Process/End
09	Error Handling	try/catch/finally, throw, Write-Error, JSON parsing
10	Capstone: File I/O	text files, CSV, JSON, mini grade tracker

Tips for Beginners

• Type commands manually first, then copy/paste later.
• Read comments in each lesson carefully; they explain both what and why.
• Run the Pester tests after changing a function to confirm behavior.
• Use Get-Help <command> often. Example: Get-Help Get-Content -Full
• Experiment in small steps instead of writing large scripts all at once.
• If a script fails, read the full error message before changing code.

Happy scripting!