While Loop

While the for loop works great when you know the exact number of iterations, the while loop is perfect when you want to keep looping until a condition becomes false.

A while loop checks its condition before each iteration. If the condition is true, the code inside runs. This continues until the condition becomes false.

<?php
$count = 1;

while ($count <= 3) {
    echo "Count: $count\n";
    $count++;
}
?>

This outputs:

Count: 1
Count: 2
Count: 3

The loop starts by checking if $count <= 3. Since it's true, the code runs and increments $count. When $count reaches 4, the condition fails and the loop stops.

Important: Always ensure something inside the loop eventually makes the condition false. Otherwise, you'll create an infinite loop that never stops running.

<?php
$total = 0;
$num = 1;

while ($total < 10) {
    $total += $num;
    $num++;
}

echo $total;
?>

This keeps adding numbers until the total reaches or exceeds 10, then outputs the final value.