What Is "match" in PHP?

Introduced in PHP 8, the match expression can be used to check a subject against multiple expressions. If a match is found, then its corresponding value is returned. The resulting value can either be stored in a variable or returned. For example:

// PHP 8+
$subject = 'expr2';

$result = match ($subject) {
    'expr1' => 'foo',
    'expr2', 'expr3' => 'bar',
    default => 'baz',
};

echo $result; // 'bar'

As you can see from the example above, the expression arms may contain multiple expressions (separated by a comma). Also, please note that only single-line expressions are supported.

match expressions must be terminated by a semi-colon (;).

match conditions (which can be any arbitrary expression) are checked top-down, in the following way:

• If a condition matches, then the corresponding value is returned and the remaining conditions are not evaluated;
• If a match is not found, then:
  • If a default exists, the value associated with the default pattern is returned;
  • Otherwise, an UnhandledMatchError is thrown.

For example:

// PHP 8+
$subject = 'no-match';

$result = match ($subject) {
    'expr1' => 'foo',
    'expr2' => 'bar',
};

// Fatal error: Uncaught UnhandledMatchError

match conditions are evaluated using strict comparison / identity check of a value (i.e. ===). For example:

// PHP 8+
echo match (8.0) {
  '8.0' => 'not expected',
  8.0 => 'expected',
}; // 'expected'

However, you can also handle non-identity conditional cases in match expressions by using true as the subject expression, for example, like so:

// PHP 8+
$version = '7.0.1';

echo match (true) {
  $version >= '7' => 'supported',
  default => 'not supported',
}; // 'supported'