====== PowerShell Cheatsheet ======

===== Basic Syntax =====
  * **Variables:** No need for explicit declaration.
    ```powershell
    $x = 5
    $name = "John"
    ```

  * **Comments:**
    ```powershell
    # This is a single-line comment

    <#
    This is a
    multi-line comment
    #>
    ```

===== Data Types =====
  * **Common Types:**
    * String: `$text = "Hello"`
    * Integer: `$x = 10`
    * Array: `$arr = @(1, 2, 3)`
    * Hashtable: `$hash = @{key = "value"}`
    * Boolean: `$flag = $true`

===== Control Flow =====
  * **If-else statement:**
    ```powershell
    if ($x -gt 5) {
        Write-Output "x is greater than 5"
    } elseif ($x -eq 5) {
        Write-Output "x is 5"
    } else {
        Write-Output "x is less than 5"
    }
    ```

  * **Loops:**
    * **For loop:**
      ```powershell
      for ($i = 0; $i -lt 5; $i++) {
          Write-Output $i
      }
      ```

    * **While loop:**
      ```powershell
      $count = 0
      while ($count -lt 5) {
          Write-Output $count
          $count++
      }
      ```

    * **Foreach loop:**
      ```powershell
      $arr = @(1, 2, 3)
      foreach ($item in $arr) {
          Write-Output $item
      }
      ```

===== Functions =====
  * **Defining a function:**
    ```powershell
    function Greet {
        param ($name)
        "Hello, $name"
    }

    Greet "John"
    ```

===== Data Structures =====
  * **Arrays:**
    ```powershell
    $arr = @(1, 2, 3)
    $arr += 4
    ```

  * **Hashtables:**
    ```powershell
    $hash = @{ "key1" = "value1"; "key2" = "value2" }
    $hash["key1"] = "newValue"
    ```

===== Error Handling =====
  * **Try-Catch-Finally Block:**
    ```powershell
    try {
        $result = 10 / 0
    } catch {
        Write-Output "An error occurred: $_"
    } finally {
        Write-Output "Execution finished"
    }
    ```

===== File Handling =====
  * **Reading a file:**
    ```powershell
    $content = Get-Content -Path "file.txt"
    Write-Output $content
    ```

  * **Writing to a file:**
    ```powershell
    "Hello, World!" | Out-File -FilePath "file.txt"
    ```

  * **Appending to a file:**
    ```powershell
    "Additional text" | Add-Content -Path "file.txt"
    ```

===== Cmdlets =====
  * **Getting Cmdlets:** `Get-Command`
  * **Cmdlet Help:** `Get-Help Get-Content`
  * **Piping:** `Get-Process | Sort-Object CPU -Descending`

===== Importing Modules =====
  * **Importing a module:**
    ```powershell
    Import-Module -Name MyModule
    ```

===== Classes & Objects =====
  * **Defining a class:**
    ```powershell
    class Person {
        [string]$Name
        [int]$Age

        Person ([string]$name, [int]$age) {
            $this.Name = $name
            $this.Age = $age
        }

        [void]Greet() {
            Write-Output "Hello, my name is $($this.Name)"
        }
    }

    $p = [Person]::new("Alice", 25)
    $p.Greet()
    ```

===== Useful Commands =====
  * **Get processes:** `Get-Process`
  * **Stop a process:** `Stop-Process -Name notepad`
  * **List services:** `Get-Service`
  * **Change directory:** `Set-Location -Path C:\`
  * **Get current directory:** `Get-Location`

===== Useful Tips =====
  * **Automatic Variables:**
    * `$?` - Status of last command (True/False)
    * `$_` - Current pipeline object
    * `$PSVersionTable` - PowerShell version information

  * **Filtering and Sorting:**
    ```powershell
    Get-Process | Where-Object {$_.CPU -gt 100} | Sort-Object -Property CPU -Descending
    ```

===== Conclusion =====
This cheatsheet provides a quick overview of essential PowerShell commands and syntax for easy reference. For more advanced features, refer to the official PowerShell documentation.