Learn POWERSHELL with Real Code Examples

$count = 0
$isDark = $false

function Update-UI {
    Write-Host "Counter: $count"
    Write-Host "Theme: $(if ($isDark) { 'Dark' } else { 'Light' })"
}

function Increment { $global:count += 1; Update-UI }
function Decrement { $global:count -= 1; Update-UI }
function Reset { $global:count = 0; Update-UI }
function Toggle-Theme { $global:isDark = -not $global:isDark; Update-UI }

# Simulate actions
Update-UI
Increment
Increment
Toggle-Theme
Decrement
Reset

Demonstrates a simple counter with theme toggling using PowerShell variables and console output.

function Add($a, $b) { $a + $b }
function Subtract($a, $b) { $a - $b }
function Multiply($a, $b) { $a * $b }
function Divide($a, $b) { $a / $b }

Write-Host "Add 5 + 3: $(Add 5 3)"
Write-Host "Subtract 5 - 3: $(Subtract 5 3)"
Write-Host "Multiply 5 * 3: $(Multiply 5 3)"
Write-Host "Divide 6 / 2: $(Divide 6 2)"

Performs basic arithmetic operations using functions.

function Factorial($n) {
    if ($n -le 1) { return 1 }
    else { return $n * (Factorial ($n - 1)) }
}

Write-Host "Factorial of 5: $(Factorial 5)"

Recursive factorial function.

function Fibonacci($n) {
    if ($n -eq 0) { return 0 }
    elseif ($n -eq 1) { return 1 }
    else { return (Fibonacci ($n - 1)) + (Fibonacci ($n - 2)) }
}

0..9 | ForEach-Object { Write-Host (Fibonacci $_) }

Generate Fibonacci numbers using recursion.

$numbers = 1..10
$squares = $numbers | Where-Object { $_ % 2 -eq 0 } | ForEach-Object { $_ * $_ }
Write-Host $squares

Square even numbers using array operations.

$scores = @{ Alice=10; Bob=5; Charlie=12 }
$highScores = $scores.GetEnumerator() | Where-Object { $_.Value -ge 10 } | ForEach-Object { $_.Name, $_.Value }
Write-Host $highScores

Filtering hashtable based on values.

$add = { param($x,$y) $x + $y }
Write-Host ($add.Invoke(3,7))

Using scriptblocks for anonymous functions.

$numbers = 1,2,3,4,5
$sum = 0
foreach ($n in $numbers) { $sum += $n }
Write-Host $sum

Sum elements of an array.

$arr1 = 1,2,3
$arr2 = 4,5,6
for ($i=0; $i -lt $arr1.Length; $i++) { Write-Host ($arr1[$i] + $arr2[$i]) }

Combine two arrays element-wise.

$str = 'HelloWorld'
$sub = $str.Substring(0,5)
$len = $str.Length
Write-Host "Substring: $sub, Length: $len"

Substring extraction and length.