The Break Statement
SHORT DESCRIPTION
A statement for immediately exiting foreach, for, while, do, or switch statements
LONG DESCRIPTION
A break statement appearing in a code block of a foreach, for, while, or do loop or in a switch statement, ends the code block. In the case of the looping statements, the break statement causes the loop to exit. In the case of the switch statement, the break statement causes a code block inside of a switch statement to exit and thus the entire switch statement exits.
The following example shows how to use a break statement to exit a for statement:
for($i=1; $i -le 10; $i++)
{
Write-Host $i
break
}
In this case, the break statement exits the for loop when $i equals 1. Even though the for statement evaluates to true until $i is greater than 10, the Windows PowerShell reaches the break statement the first time through the for loop.
It's more common to see the break statement used inside of a loop where there is some inner condition to be met. Consider the following foreach statement example:
$i=0
$varB = 10,20,30,40
foreach ($val in $varB)
{
$i++
if ($val -eq 30)
{
break
}
}
Write-Host "30 was found in array position $i"
In this example, the foreach statement iterates the $varB array. Each time through the code block, the $i variable is incremented by 1. The if statement inside evaluates to false the first two times through the loop. The third time through the loop, $i equals 3 and the $val variable equals 30, at which point the break statement runs and the foreach loop exits.
Breaking out of the other looping statements is identical to how you break out of the foreach loop. In the following example, the break statement exits a while statement when a DivideByZeroException is trapped using the trap statement.
$i = 3
while ($true)
{
trap [DivideByZeroException]
{
Write-Host "divide by zero trapped"
break
}
1 / $i--
}
A switch statement is not a looping construct, but the break statement is useful for ending the program flow when a particular condition is met. For example, the following switch statement uses break statements to test for the most specific condition:
$var ="word2"
switch -regex ($var)
{
"word2"
{
Write-Host "Exact" $_
break
}
"word.*"
{
Write-Host "Match on the prefix" $_
break
}
"w.*"
{
Write-Host "Match on at least the first letter" $_
break
}
default
{
Write-Host "No match" $_
break
}
}
In this example, $var is created and initialized to a string value of "word2". The switch statement uses regex (a regular expression .NET class) to match the variable value first with the term "word2". Because the variable value and the first test in the switch statement match, the first code block in the switch statement runs. When PowerShell reaches the first break statement, the switch statement exits. If the four break statements were removed from the example, then all four conditions would be met. Thus, this example uses the break statement to display results when the most specific condition is met.
SEE ALSO
For information about using comparison operators, enter the following command at the PowerShell command prompt:
For information about the switch statement, enter the following
command:
help about_switch
For information about the foreach statement, enter the following
command:
help about_foreach
For information about the for statement, enter the following command:
help about_for
For information about the while statement, enter the following command:
help about_while