PHP Match Expression (match)

The PHP match expression is a powerful feature introduced in PHP 8.0 that provides a more concise and flexible alternative to switch statements.

Basic Match Syntax

$result = match ($value) {

  pattern1 => expression1,

  pattern2 => expression2,

  // ...

  default => default_expression,

};

Comparison switch vs match

// switch statement

switch ($statusCode) {

   case 200:

       $message = 'OK';

       break;

   case 404:

       $message = 'Not Found';

       break;

   case 500:

       $message = 'Server Error';

       break;

   default:

       $message = 'Unknown';

}

// match equivalent

$message = match ($statusCode) {

  200 => 'OK',

   404 => 'Not Found',

   500 => 'Server Error',

   default => 'Unknown',

};

Various Usage Examples:

 // multiple conditions

 $result = match ($httpCode) {

    200, 201, 202 => 'Success',

    400, 401, 403 => 'Client Error',

    500, 501, 502 => 'Server Error',

    default => 'Unknown',

 };

 // Match uses strict comparison (===)

 $result = match ($value) {

    0 => 'Integer zero',

    '0' => 'String zero',

    false => 'Boolean false',

    default => 'Other',

 };

 // Complex Expressions

 $age = 25;

 $category = match (true) {

    $age < 13 => 'Child',

    $age < 20 => 'Teenager',

    $age < 65 => 'Adult',

    default => 'Senior',

 };

 // returning different types

 function processValue($value) {

    return match ($value) {

        'int' => 42,

        'string' => 'Hello World',

        'array' => [1, 2, 3],

        'bool' => true,

        default => null,

    };

 }

 // Using with arrays

 $user = [

    'role' => 'admin',

    'status' => 'active'

 ];

 $permissions = match ($user['role']) {

    'admin' => ['read', 'write', 'delete'],

    'editor' => ['read', 'write'],

    'viewer' => ['read'],

    default => [],

 };

 // nested match expressions

 $result = match ($type) {

    'number' => match ($value) {

        $value > 0 => 'Positive',

        $value < 0 => 'Negative',

        default => 'Zero',

    },

    'string' => 'String type',

    default => 'Unknown type',

 };

 // Conditional Logic in Patterns

 $score = 85;

 $grade = match (true) {

    $score >= 90 => 'A',

    $score >= 80 => 'B',

    $score >= 70 => 'C',

    $score >= 60 => 'D',

    default => 'F',

 };

Advantages Over Switch

- Returns a value - Can be assigned directly to variables
- No fall-through - Prevents accidental bugs
- Strict comparisons - More predictable behavior
- More concise - Less boilerplate code
- Better error handling - Throws UnhandledMatchError for unhandled cases

Important Notes
- Match expressions must be exhaustive or include a default case
- Throws UnhandledMatchError if no pattern matches and no default is provided
- Each arm must be a single expression (use anonymous functions for complex logic)
- Patterns are evaluated in order, first match wins

The match expression is a significant improvement that makes conditional logic more readable, safer, and more expressive in modern PHP code.