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run code in 500+ PHP versions simultaneously
<?php namespace A { function print_r($x) { print 'No print_r for you!'.PHP_EOL; } } namespace A { $x = []; print_r($x); } // It looks like it, but // A\B is not a child of A!! namespace A\B { // Just print_r for you, with fallback print_r($x); } ?>

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