A Match Made in PHP

PHP is often criticized for being a bad language. Developers often point to the

• inconsistent function names
• inconsistent parameter order
• a history of insecure mysql functions
• there is a lot of bad PHP code in the world

Despite these criticisms (though the last isn’t really PHP’s fault), PHP remains a very popular web language choice. There are plenty of mature , well-tested frameworks to make getting started easy. Composer is an excellent package manager and there are no shortage of testing libraries .

Yet, PHP consistently ranks near the middle of the pack of desired and admired technologies in the StackOverflow Developer Survey . PHP is perhaps the boring choice. But boring isn’t necessarily bad. Boring can means stable which means capital investment can proceed more confidently.

This isn’t to say there aren’t still quality-of-life improvements happening in the PHP world. PHP 8 brought in the new JIT compiler, more type hinting, attributes, and other new language features.

One such quality-of-life language feature is PHP’s new match statement. You can think of it as a fancy ternary statement with more flexibility.

Here’s an example of how match works in action:

$suit = 'hearts';

$suit_string = match ($suit) {
    'spades' => 'We are holding spades',
    'clubs' => 'We are holding clubs',
    'hearts' => 'We are holding hearts',
    'diamonds' => 'We are holding diamonds',
    default => 'unknown'
};

print($suit_string); // Prints "We are holding hearts"

The syntax is fairly easy to understand even to someone who hasn’t seen it before. We are assigning a variable on the condition that a variable matches a set of conditions. This is very similar to the switch statement, but there are a couple differences.

1. The match function uses an identity check (===) where the switch statement uses a weak equality check (==) (2 === '2' will return false).
2. The match expression returns a value. The case statement doesn’t return anything.
3. The match expression can perform non-identity checks.

The match syntax is much less verbose than switch, especially if a variable is being set.

Here’s the logical equivalent using switch:

$suit = 'hearts';

$suit_string = '';

switch ($suit) {
    case 'spades':
        $suit_string = 'We are holding spades';
        break;
    case 'clubs':
        $suit_string = 'We are holding clubs';
        break;
    case 'hearts':
        $suit_string = 'We are holding hearts';
        break;
    case 'diamonds':
        $suit_string = 'We are holding diamonds';
        break;
    default:
        $suit_string = 'unknown';
}

print($suit_string); // Prints "We are holding hearts"

Look at all those extra break; and case statements and variable assignment operations. Gross!

Something else switch cannot do that match can: perform non-identity checks (===) by passing true into the subject expression:

$old_decades = ['1940s', '1950s', '1960s', '1970s', '1980s'];
$selected_decade = '1990s';

$output = match (true) {
    in_array($selected_decade, $old_decades) => 'The selected decade is old!',
    $selected_decade === '1990s' => 'The selected decade is not old!'
};

print($output); // Prints "The selected decade is not old!"

This is a new level of succinctness, power, and expression. Once you start using match it’s easy to see many useful applications. Here’s the classic fizzbuzz program implemented using match:

$n = 100;

for ($i = 1; $i <= $n; $i++) {
    print match(0) {
        $i % 3 + $i % 5 => "FizzBuzz" . PHP_EOL,
        $i % 3 => "Fizz" . PHP_EOL,
        $i % 5 => "Buzz" . PHP_EOL,
        default => $i . PHP_EOL
    };
}

// 1
// 2
// Fizz
// 4
// Buzz
// Fizz
// 7
// 8
// Fizz
// Buzz
// 11
// Fizz
// 13
// 14
// FizzBuzz
// 16
// ...

That was simple with clear, readable syntax!