about_If

TOPIC
	about_If

SHORT DESCRIPTION
	Describes a language command you can use to run statement lists based 
	on the results of one or more conditional tests.


LONG DESCRIPTION
	You can use the If statement to run code blocks if a specified 
	conditional test evaluates to true. You can also specify one or more 
	additional conditional tests to run if all the prior tests evaluate to 
	false. Finally, you can specify an additional code block that is run if 
	no other prior conditional test evaluates to true. 


  Syntax
	The following example shows the If statement syntax:


		if (<test1>) 
			{<statement list 1>}
		[elseif (<test2>)
			{<statement list 2>}]
		[else
			{<statement list 3>}]


	When you run an If statement, Windows PowerShell evaluates the 
	<test1> conditional expression as true or false. If <test1> is true, 
	<statement list 1> runs, and Windows PowerShell exits the If statement. 
	If <test1> is false, Windows PowerShell evaluates the condition specified
	by the <test2> conditional statement. 


	If <test2> is true, <statement list 2> runs, and Windows PowerShell 
	exits the If statement. If both <test1> and <test2> evaluate to false,
	the <statement list 3> code block runs, and Windows PowerShell exits 
	the If statement. 


	You can use multiple Elseif statements to chain a series of conditional 
	tests so that each test is run only if all the previous tests are 
	false. If you need to create an If statement that contains many 
	Elseif statements, consider using a Switch statement instead.


  Examples
	The simplest If statement contains a single command
	and does not contain any Elseif statements or any Else statements. The 
	following example shows the simplest form of the If statement:


		if ($a -gt 2)
		{
			Write-Host "The value $a is greater than 2."
	}


	In this example, if the $a variable is greater than 2, the condition 
	evaluates to true, and the statement list runs. However, if $a is less
	than or equal to 2 or is not an existing variable, the If statement does
	not display a message. By adding an Else statement, a message is displayed
	when $a is less than or equal to 2, as the next example shows:


		if ($a -gt 2)
		{
			Write-Host "The value $a is greater than 2."
	}
		else
		{
			Write-Host "The value $a is less than or equal to 2, is not 
		created or is not initialized."
	}


	To further refine this example, you can use the Elseif statement to 
	display a message when the value of $a is equal to 2, as the next 
	example shows:


		if ($a -gt 2)
		{
			Write-Host "The value $a is greater than 2."
	}
		elseif ($a -eq 2)
		{
			Write-Host "The value $a is equal to 2."
	}
		else
		{
			Write-Host "The value $a is less than 2 or was not created 
		or initialized."
	}


SEE ALSO
	about_Comparison_Operators
	about_Switch