3v4l.org

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<?php $start = 6; $list = [ '1楼', '2楼', '3楼', '4楼', '5楼', ]; $list = array_flip( array_map( array_flip($list), function($key){ return $start+(int)$key; } ) );

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47.32 ms | 402 KiB | 5 Q