The Continue Statement in PHP

In addition to the break statement, which terminates a loop, there is also the continue statement, which starts a new iteration of the loop. This statement can sometimes be useful for simplifying code, although almost any task can be solved without it. Let's look at a practical example.

Suppose we are given an array with numbers. Let's loop through it and square the numbers divisible by 2, then output them to the screen, and cube the numbers divisible by 3, then output them to the screen.

Here is the solution to the described task:

<?php
	$arr = [1, 2, 3, 4, 5, 6, 7, 8, 9];
	
	foreach ($arr as $elem) {
		if ($elem % 2 === 0) {
			$res = $elem * $elem;
			echo $res;
		} elseif ($elem % 3 === 0) {
			$res = $elem * $elem * $elem;
			echo $res;
		}
	}
?>

As you can see, the line echo $res is repeated twice. Let's move it out of the if, like this:

<?php
	$arr = [1, 2, 3, 4, 5, 6, 7, 8, 9];
	
	foreach ($arr as $elem) {
		if ($elem % 2 === 0) {
			$res = $elem * $elem;
		} elseif ($elem % 3 === 0) {
			$res = $elem * $elem * $elem;
		}
		
		echo $res; // moved output out of the condition
	}
?>

Now, however, our script works a bit differently: it turns out that for regular elements, not processed by our if, the output of the variable $res will also be executed, which according to the conditions of our task we do not need.

Let's fix the problem by adding an else condition to our if, which will trigger for elements not divisible by 2 and 3, and call the continue statement there, which will immediately throw us to the next iteration of the loop:

<?php
	$arr = [1, 2, 3, 4, 5, 6, 7, 8, 9];
	
	foreach ($arr as $elem) {
		if ($elem % 2 === 0) {
			$res = $elem * $elem;
		} elseif ($elem % 3 === 0) {
			$res = $elem * $elem * $elem;
		} else {
			continue; // move to the next loop iteration
		}
		
		echo $res; // will execute if divisible by 2 or 3
	}
?>

Write a loop that outputs only even numbers from 1 to 100, skipping odd numbers using continue.