---
title: PowerShell Classes
tags: [powershell, oop, classes, scripting, programming]
---

# PowerShell Classes

PowerShell 5.0 introduced a formal syntax for defining classes and other user-defined types, bringing object-oriented programming (OOP) concepts directly into the language.

**Parent Topic:** [[programming/PowerShell/Scripting|PowerShell Scripting and Programming]]
**Related:** [[programming/PowerShell/PowerShell|PowerShell Comprehensive Guide]]

## 1. Defining a Class

A class is a blueprint for creating objects. It encapsulates data (properties) and behavior (methods).

```powershell
class Computer {
    # Properties
    [string]$Hostname
    [string]$OperatingSystem
    [int]$RamGB

    # Methods
    [string] GetStatus() {
        return "Computer '$($this.Hostname)' is running $($this.OperatingSystem)."
    }
}
```

### Instantiating a Class
You create an "instance" of a class using `[ClassName]::new()` or `New-Object`.

```powershell
$server = [Computer]::new()
$server.Hostname = "SRV01"
$server.OperatingSystem = "Windows Server 2022"
$server.RamGB = 64

$server.GetStatus()
# Output: Computer 'SRV01' is running Windows Server 2022.
```

## 2. Constructors

Constructors are special methods that run when a new object is created, allowing you to initialize its properties.

```powershell
class Server {
    [string]$Hostname
    [string]$IPAddress

    # Default constructor
    Server() {
        $this.Hostname = "localhost"
        $this.IPAddress = "127.0.0.1"
    }

    # Overloaded constructor with parameters
    Server([string]$Hostname, [string]$IPAddress) {
        $this.Hostname = $Hostname
        $this.IPAddress = $IPAddress
    }
}

$defaultSrv = [Server]::new()
$customSrv = [Server]::new("WEB01", "192.168.1.10")
```

## 3. Inheritance

Inheritance allows a class to inherit properties and methods from a "base" class. This promotes code reuse.

```powershell
class VirtualMachine : Computer {
    # Inherits Hostname, OperatingSystem, RamGB, and GetStatus() from Computer

    # New property specific to VirtualMachine
    [string]$Hypervisor

    # Overriding a method
    [string] GetStatus() {
        # Call the parent method and add to it
        $parentStatus = [super]::GetStatus()
        return "$parentStatus on hypervisor $($this.Hypervisor)."
    }
}

$vm = [VirtualMachine]::new()
$vm.Hostname = "VM-TEST01"
$vm.OperatingSystem = "Ubuntu 24.04"
$vm.Hypervisor = "Hyper-V"

$vm.GetStatus()
# Output: Computer 'VM-TEST01' is running Ubuntu 24.04. on hypervisor Hyper-V.
```
*   **`[super]::GetStatus()`**: This syntax allows you to call the method from the parent class.

## 4. Static Properties and Methods

Static members belong to the class itself, not to an instance of the class. You access them using `[ClassName]::Member`.

```powershell
class Logger {
    static [string]$LogPath = "C:\Logs\app.log"

    static [void] Write([string]$Message) {
        $timestamp = Get-Date
        Add-Content -Path [Logger]::LogPath -Value "[$timestamp] - $Message"
    }
}

# No instance needed
[Logger]::Write("Application started.")
```

---
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