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<?php $array = [ [ 'name' => 'Foo', 'children' => [ [ 'name' => 'B', 'children' => [] ], [ 'name' => 'A', 'children' => [] ] ] ], [ 'name' => 'Bar', 'children' => [ [ 'name' => 'Z', 'children' => [] ], [ 'name' => 'X', 'children' => [] ], [ 'name' => 'Y', 'children' => [] ] ] ] ]; usort($array, $f = function(&$x, &$y) use (&$f){ usort($x['children'], $f); //usort($y['children'], $f); return strcasecmp($x['name'], $y['name']); }); var_dump($array);

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