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run code in 300+ PHP versions simultaneously
<?php function findBase(string $t): string|null { $matches = []; preg_match('/(?P<name>\.([^\.])*)$/', $t, $matches); if (!isset($matches['name'])) { return $t; }; return substr($t, 0, -1 * strlen($matches['name'])); } var_dump(findBase('')); var_dump(findBase('foo')); var_dump(findBase('foo.bar')); var_dump(findBase('foo.bar.baz')); var_dump(findBase('foo.bar[0].baz'));
Output for 8.0.1 - 8.0.30, 8.1.0 - 8.1.29, 8.2.0 - 8.2.23, 8.3.0 - 8.3.11
string(0) "" string(3) "foo" string(3) "foo" string(7) "foo.bar" string(10) "foo.bar[0]"

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65.02 ms | 406 KiB | 5 Q