PS-CheatSheet.ps1

# Output
Write-Output "Hello, World!"  # Outputs: Hello, World!

# Variables
$x = 5  # Integer variable
$name = "Alice"  # String variable
$a, $b, $c = 1, 2, 3  # Multiple assignments

# Data Types
$integer = 10  # [int]
$float = 3.14  # [double]
$string = "Hello"  # [string]
$boolean = $true  # [bool]
$array = @(1, 2, 3)  # Array
$hashtable = @{name = "Alice"; age = 25 }  # Hashtable (similar to dict)
$set = [System.Collections.Generic.HashSet[object]]::new($array)  # Set

# Control Flow
if ($x -gt 0) {
    Write-Output "x is positive"
}
elseif ($x -eq 0) {
    Write-Output "x is zero"
}
else {
    Write-Output "x is negative"
}

for ($i = 0; $i -lt 5; $i++) {
    Write-Output $i  # Loops through numbers 0 to 4
}

while ($x -lt 10) {
    $x++  # Increment by 1
}

# Functions
function My-Function {
    return "Hello from the function!"
}

# String Operations
$upper = "Hello".ToUpper()  # "HELLO"
$lower = "HELLO".ToLower()  # "hello"
$split = "Hello World" -split " "  # ['Hello', 'World']
$join = -join ('a', 'b', 'c')  # 'abc'
$replace = "Hello" -replace "H", "J"  # "Jello"
$length = "Hello".Length  # 5

# Array/List Operations
$array += 4  # Adds 4 to $array
$array = $array -ne 2  # Removes 2 from $array
$array = $array | Sort-Object  # Sorts $array in ascending order
$array = $array | Sort-Object -Descending  # Sorts $array in descending order

# Hashtable Operations
$hashtable["age"]  # Access the value associated with the key 'age'
$hashtable["age"] = 26  # Modify the value for 'age'
$keys = $hashtable.Keys  # Returns all keys
$values = $hashtable.Values  # Returns all values

# File Operations
$file = "file.txt"
$content = Get-Content $file  # Reads the entire file content
Set-Content $file -Value "New content"  # Writes to a file
Add-Content $file -Value "Append content"  # Appends to a file

# Error Handling
try {
    Throw "Error"
}
catch {
    Write-Output "Caught an error: $_"
}
finally {
    Write-Output "This runs no matter what"
}

# Importing Modules
Import-Module Microsoft.Graph  # Import a specific module

# Commonly Used Functions
$length = $array.Length  # Returns the number of items in $array
$dataType = $x.GetType()  # Returns the type of $x
$sum = $array | Measure-Object -Sum  # Sums all items in $array
$max = $array | Measure-Object -Maximum  # Returns the max value
$round = [math]::Round(3.14159, 2)  # Rounds to 2 decimal places

# List Comprehensions (PowerShell doesn't support list comprehensions directly, but similar results can be achieved)
$squares = for ($i = 0; $i -lt 10; $i++) { $i * $i }

# Lambda Functions (ScriptBlock in PowerShell)
$increment = { param($x) $x + 1 }
$increment.Invoke(5) # This will return 6.

# Classes
class MyClass {
    [string]$name
    MyClass ([string]$name) {
        $this.name = $name
    }

    [string] Greet() {
        return "Hello, $($this.name)!"
    }
}

$myObject = [MyClass]::new("Alice")
Write-Output $myObject.Greet()  # Outputs: Hello, Alice!