SwitchPerformanceTest.ps1

function RangeOperatorInFunc($Value) {
	switch($Value) {
		{0..24 -contains $_} { $a = 0 }
		{25..49 -contains $_} { $a = 1 }
		{50..74 -contains $_} { $a = 2 }
		{75..99 -contains $_} { $a = 3 }
	}
}

$gr1 = 0..24;
$gr2 = 24..49;
$gr3 = 50..74;
$gr4 = 75..99;

function CachedValuesNotInScope($Value) {
	switch($Value) {
		{$gr1 -contains $_} { $a = 0 }
		{$gr2 -contains $_} { $a = 1 }
		{$gr3 -contains $_} { $a = 2 }
		{$gr4 -contains $_} { $a = 3 }
	}
}

$global:hr1 = 0..24;
$global:hr2 = 24..49;
$global:hr3 = 50..74;
$global:hr4 = 75..99;

function CachedValuesWithScopedPrefixed($Value) {
	switch($Value) {
		{$global:hr1 -contains $_} { $a = 0 }
		{$global:hr2 -contains $_} { $a = 1 }
		{$global:hr3 -contains $_} { $a = 2 }
		{$global:hr4 -contains $_} { $a = 3 }
	}
}


Write-Host "All Times in Ticks (from Measure-Command)`r`n"

$r = New-Object System.Random
#$r.next(100)

function BaselineFunctionWithoutSwitch($Value) {
	$a = 0
}

$baseFuncTicks = @()
for($i = 0; $i -lt 10000; $i++) {
	$k = $r.Next(100)
	$m = Measure-Command { BaselineFunctionWithoutSwitch($k) }
	$baseFuncTicks += @($m)
}

$baseAvgTicks = ($baseFuncTicks.Ticks | Measure-Object -Average).Average
"Calling a Function Overhead = $baseAvgTicks`r`n"

$timeComparisons = @()
function New-TC($Description, $Measure, $BaseAvgTicks) {
	$ticks = ($Measure.Ticks | Measure-Object -Average).Average
	$switchTicks = $ticks - $BaseAvgTicks

	return [PSCustomObject] @{
		Description = $Description
		'Switch Avg Execution Time' = $switchTicks
		'Total Avg Execution Time' = $ticks
	}
}

$ftimes = @()
for($i = 0; $i -lt 10000; $i++) {
	$k = $r.Next(100)
	$m = Measure-Command { RangeOperatorInFunc($k) }
	$ftimes += @($m)
}
$timeComparisons += @(New-TC -Description "Range Operator in Func" -Measure $ftimes -BaseAvgTicks $baseAvgTicks)


$gtimes = @()
for($i = 0; $i -lt 10000; $i++) {
	$k = $r.Next(100)
	$m = Measure-Command { CachedValuesNotInScope($k) }
	$gtimes += @($m)
}
$timeComparisons += @(New-TC -Description "Cached Values not in Func Scope" -Measure $gtimes -BaseAvgTicks $baseAvgTicks)



$htimes = @()
for($i = 0; $i -lt 10000; $i++) {
	$k = $r.Next(100)
	$m = Measure-Command { CachedValuesWithScopedPrefixed($k) }
	$htimes += @($m)
}
$timeComparisons += @(New-TC -Description "Explicitly Scoped Cached Values" -Measure $htimes -BaseAvgTicks $baseAvgTicks)


$itimes = @()
for($i = 0; $i -lt 10000; $i++) {
	$k = $r.Next(100)
	$m = Measure-Command {
		switch($Value) {
			{0..24 -contains $_} { $a = 0 }
			{25..49 -contains $_} { $a = 1 }
			{50..74 -contains $_} { $a = 2 }
			{75..99 -contains $_} { $a = 3 }
		}
	}
	$itimes += @($m)
}
$timeComparisons += @(New-TC -Description "Range Operator with No Func" -Measure $times -BaseAvgTicks 0)

$timeComparisons