powershell-windows

PowerShell Windows Patterns

Critical patterns and pitfalls for Windows PowerShell.

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1. Operator Syntax Rules

CRITICAL: Parentheses Required

❌ Wrong	✅ Correct
if (Test-Path "a" -or Test-Path "b")	if ((Test-Path "a") -or (Test-Path "b"))
if (Get-Item $x -and $y -eq 5)	if ((Get-Item $x) -and ($y -eq 5))

Rule: Each cmdlet call MUST be in parentheses when using logical operators.

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2. Unicode/Emoji Restriction

CRITICAL: No Unicode in Scripts

Purpose	❌ Don't Use	✅ Use
Success	✅ ✓	[OK] [+]
Error	❌ ✗ 🔴	[!] [X]
Warning	⚠️ 🟡	[*] [WARN]
Info	ℹ️ 🔵	[i] [INFO]
Progress	⏳	[...]

Rule: Use ASCII characters only in PowerShell scripts.

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3. Null Check Patterns

Always Check Before Access

❌ Wrong	✅ Correct
$array.Count -gt 0	$array -and $array.Count -gt 0
$text.Length	if ($text) { $text.Length }

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4. String Interpolation

Complex Expressions

❌ Wrong	✅ Correct
"Value: $($obj.prop.sub)"	Store in variable first

Pattern:

$value = $obj.prop.sub
Write-Output "Value: $value"

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5. Error Handling

ErrorActionPreference

Value	Use
Stop	Development (fail fast)
Contin