PowerShell Loops
last modified February 15, 2025
In this article, we will explore loops in PowerShell.
In PowerShell, loops are control structures that allow you to
execute a block of code repeatedly based on a condition. They are essential for
automating repetitive tasks and processing collections of data. Common types of
loops in PowerShell include for, foreach,
while, and do-while loops.
The for loop
runs a specified number of times based on an initializer, condition, and
incrementer. The foreach loop iterates over each item in a
collection, such as an array or list. The while loop continues to
execute as long as the specified condition is true, and the
do-while loop ensures the code block runs at least once before
checking the condition. By using loops, you can simplify complex
tasks and enhance the efficiency of your scripts.
For loop
The for loop is a control flow statement that allows code to be executed repeatedly.
for ($i=1; $i -le 5; $i++) {
Write-Output "Number: $i"
}
In this example, we use a for loop to print the numbers from 1 to 5.
for ($i=1; $i -le 5; $i++) {
Write-Output "Number: $i"
}
The for loop has three parts: initialization, condition, and increment.
$i=1
We initialize the variable $i to 1.
$i -le 5
We check if the value of $i is less than or equal to 5.
$i++
We increment the value of $i by 1.
PS C:\> .\for_loop.ps1 Number: 1 Number: 2 Number: 3 Number: 4 Number: 5
The output shows the numbers from 1 to 5.
Foreach loop
The foreach loop is used to iterate over the items in a collection.
$fruits = @("apple", "banana", "cherry")
foreach ($fruit in $fruits) {
Write-Output "Fruit: $fruit"
}
In this example, we use a foreach loop to print each fruit in the $fruits array.
$fruits = @("apple", "banana", "cherry")
We create an array $fruits containing three fruit names.
foreach ($fruit in $fruits) {
Write-Output "Fruit: $fruit"
}
We use a foreach loop to iterate over each item in the $fruits array.
PS C:\> .\foreach_loop.ps1 Fruit: apple Fruit: banana Fruit: cherry
The output shows each fruit in the $fruits array.
While loop
The while loop is a control flow statement that allows code to be executed repeatedly while a certain condition is true.
$i = 1
while ($i -le 5) {
Write-Output "Number: $i"
$i++
}
In this example, we use a while loop to print the numbers from 1 to 5.
$i = 1
We initialize the variable $i to 1.
while ($i -le 5) {
Write-Output "Number: $i"
$i++
}
We check if the value of $i is less than or equal to 5. If it is, we print the value of $i and increment it by 1.
PS C:\> .\while_loop.ps1 Number: 1 Number: 2 Number: 3 Number: 4 Number: 5
The output shows the numbers from 1 to 5.
Do while loop
The do while loop is a control flow statement that allows code to be executed repeatedly while a certain condition is true.
$i = 1
do {
Write-Output "Number: $i"
$i++
} while ($i -le 5)
In this example, we use a do while loop to print the numbers from 1 to 5.
$i = 1
We initialize the variable $i to 1.
do {
Write-Output "Number: $i"
$i++
} while ($i -le 5)
We execute the code block first and then check if the value of $i is less than or equal to 5. If it is, we print the value of $i and increment it by 1.
PS C:\> .\do_while_loop.ps1 Number: 1 Number: 2 Number: 3 Number: 4 Number: 5
The output shows the numbers from 1 to 5.
Source
In this article, we have explored loops in PowerShell.
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