Coming from languages like C# where semicolons are mandatory, many developers instinctively include them in PowerShell. But unlike C# or JavaScript, PowerShell treats semicolons as optional statement terminators rather than required syntax elements. Here's what you need to know about this scripting language's unique approach.

While generally optional, semicolons serve crucial purposes in specific scenarios:

# 1. Multiple statements on one line
$var1 = 1; $var2 = 2; Write-Output ($var1 + $var2)

# 2. Inline loops/conditionals in pipelines
Get-Process | Where-Object { $_.CPU -gt 10 }; Stop-Service -Name "BITS"

# 3. Switch statement cases
switch ($value) {
    1 { Write-Output "Case 1"; break }
    2 { Write-Output "Case 2"; break }
}

PowerShell's flexible approach creates interesting style considerations:

• Pro-semicolon: Maintains consistency with other languages and makes multi-statement lines clearer
• Anti-semicolon: Reduces visual clutter since PowerShell was designed without requiring them

Compare these equivalent snippets to see the difference:

# Without semicolons
function Get-DiskInfo {
    $disks = Get-PhysicalDisk
    foreach ($disk in $disks) {
        [PSCustomObject]@{
            DeviceID = $disk.DeviceID
            Size = "$($disk.Size/1GB) GB"
        }
    }
}

# With semicolons
function Get-DiskInfo {
    $disks = Get-PhysicalDisk;
    foreach ($disk in $disks) {
        [PSCustomObject]@{
            DeviceID = $disk.DeviceID;
            Size = "$($disk.Size/1GB) GB";
        };
    };
}

Contrary to some beliefs, semicolons don't affect execution speed. The PowerShell parser handles both styles identically after initial interpretation. The real impact is on:

• Code maintenance (especially in team environments)
• Parser behavior in edge cases
• Consistency with other scripts/modules you might interact with

In professional environments, consider these guidelines:

1. Follow your team's existing style guide if one exists
2. Be consistent within each script or module
3. Use semicolons when their absence could cause ambiguity
4. Document your style decisions in README files

Watch for these cases where semicolon usage affects interpretation:

# Without semicolon - interpreted as pipeline
Get-ChildItem 
Where-Object { $_.Length -gt 1MB }

# With semicolon - two separate statements
Get-ChildItem;
Where-Object { $_.Length -gt 1MB }

Coming from languages like C# where semicolons are mandatory, many developers naturally carry this habit into PowerShell. However, PowerShell's handling of statement terminators follows different conventions that warrant closer examination.

PowerShell is designed as both a shell language and scripting language, which explains its lenient approach to semicolons:

# Both are valid in PowerShell
Get-Process
Get-Process;

The parser uses newlines as implicit statement terminators, making semicolons optional in most cases.

There are specific scenarios where semicolons are required or recommended:

# Multiple statements on one line
$process = Get-Process; $count = $process.Count

# In pipelines where newlines would break the flow
Get-Process | Where-Object {$_.CPU -gt 100} | Stop-Process -WhatIf;

# After flow control statements in one-liners
if ($condition) { Do-Something }; else { Do-SomethingElse }

Based on community standards and PowerShell team recommendations:

1. Use semicolons when putting multiple statements on one line
2. Omit semicolons when each statement occupies its own line
3. Be consistent within a given script or project
4. Consider using semicolons in shared/team codebases for clarity

Contrary to some beliefs, semicolons have no impact on execution speed. The parsing difference is negligible:

Measure-Command { 1..1000 | ForEach-Object { Get-Process } }
Measure-Command { 1..1000 | ForEach-Object { Get-Process; } }

The decision often comes down to readability rather than technical requirements:

# More readable without semicolons
$services = Get-Service
$running = $services | Where-Object Status -eq 'Running'

# Sometimes clearer with semicolons
try { Dangerous-Operation } catch { Write-Error $_ }; Finalize-Operation