Why control flow directs execution in PowerShell

Introduction

Control flow tells the script what to do next. It helps decide which parts run and when, so your script works step by step.

When you want to repeat a task multiple times, like checking files every minute.

When you need to choose between two or more actions, like asking if a user wants to continue.

When you want to stop running a script if something goes wrong.

When you want to run different code based on a condition, like if a number is big or small.

Syntax

PowerShell

if (<condition>) {
    # code to run if condition is true
} elseif (<another condition>) {
    # code if second condition is true
} else {
    # code if no conditions are true
}

while (<condition>) {
    # code to repeat while condition is true
}

for (<init>; <condition>; <change>) {
    # code to repeat with a counter
}

Conditions are expressions that are either true or false.

Curly braces { } group the code that runs together.

Examples

Checks if age is 18 or more, then prints a message.

PowerShell

if ($age -ge 18) {
    Write-Output "You can vote."
} else {
    Write-Output "You are too young to vote."
}

Repeats printing count while it is less than 5.

PowerShell

while ($count -lt 5) {
    Write-Output "Count is $count"
    $count++
}

Runs the loop 3 times, printing the number each time.

PowerShell

for ($i = 1; $i -le 3; $i++) {
    Write-Output "Number $i"
}

Sample Program

This script checks the value of $number and prints a message based on its value.

PowerShell

$number = 7
if ($number -gt 10) {
    Write-Output "Number is greater than 10"
} elseif ($number -eq 7) {
    Write-Output "Number is exactly 7"
} else {
    Write-Output "Number is 10 or less and not 7"
}

Important Notes

Use control flow to make your scripts smart and flexible.

Always test your conditions to avoid unexpected results.

Indent your code inside braces to keep it readable.

Summary

Control flow guides which parts of a script run and when.

Use if, elseif, else to choose between actions.

Use loops like while and for to repeat actions.