Loops

PowerShell has several loops. You'll use foreach and ForEach-Object most.

foreach — loop over a collection

$fruits = 'apple', 'banana', 'cherry'
foreach ($fruit in $fruits) {
  "I like $fruit"
}

I like apple
I like banana
I like cherry

ForEach-Object — loop in a pipeline

1..3 | ForEach-Object { "Pass $_" }
'ada', 'linus' | ForEach-Object { $_.ToUpper() }

Pass 1
Pass 2
Pass 3
ADA
LINUS

foreach (the statement) works on a collection already in memory and is faster; ForEach-Object (the cmdlet) processes objects as they flow through a pipeline, one at a time — better for very large or streaming input.

for, while, do

for ($i = 10; $i -gt 0; $i -= 3) {
  $i
}

$balance = 100
$months = 0
while ($balance -lt 200) {
  $balance *= 1.1
  $months++
}
"Doubled after $months months"

$attempt = 0
do {
  $attempt++
  "Attempt $attempt"
} until ($attempt -ge 2)

10
7
4
1
Doubled after 8 months
Attempt 1
Attempt 2

• for — a counting loop.
• while — repeats while the condition is true (checked first).
• do { } while (...) / do { } until (...) — checks after each pass, so the body runs at least once.

break and continue

foreach ($n in 1..10) {
  if ($n % 2 -eq 0) { continue }
  if ($n -gt 7) { break }
  $n
}

1
3
5
7

Common mistakes

• Using continue or break inside ForEach-Object — they don't skip one item; they end the whole script block pipeline (or even the script). In ForEach-Object, use return to skip to the next object.

Practice

Print the 5 times table from 5 x 1 = 5 to 5 x 10 = 50.

foreach ($n in 1..10) {
  "5 x $n = $(5 * $n)"
}

5 x 1 = 5
5 x 2 = 10
5 x 3 = 15
5 x 4 = 20
5 x 5 = 25
5 x 6 = 30
5 x 7 = 35
5 x 8 = 40
5 x 9 = 45
5 x 10 = 50