Elegantly Using Switch in Place of a Long IF Conditional Expression

When you have a need to check for multiple possible values in a single variable, often the switch conditional is a preferred alternative to a long if ((...) || (...) || (...) ...) conditional expression.

Let's say, you want to display an advertising banner only on a number of certain pages:

index.php

switch ($page_name) {

	case 'about-us.php':
	case 'contact-us.php':
	case 'reviews.php':
	case 'index.php':
		
		?>
		<div class="ad">
			<figure>
				<a href="featured-products.php">
					<img src="images/ad-banner.jpg"
						alt="a photo demonstrating our featured products"></a>
			</figure>
		</div>
		<?php
		
		break;
} // end of SWITCH.

Apart from a more elegant code, another benefit of this design is that each possible case can be removed, or a new one added without breaking the PHP syntax, as there are no opening and closing parenthesis and logical OR, ||.

On the other hand when using IF, for that case, you'd need to go more carefully about editing its conditional expression:

if (
	($page_name === 'about-us.php') // Removing this line will result in a parse error!
		|| ($page_name === 'contact-us.php')
		|| ($page_name === 'reviews.php')
		|| ($page_name === 'index.php')
) {
	// ...Display Advertisement...
}

Elegantly Using Switch in Place of a Long IF Conditional Expression

This page was last updated on February 25, 2021