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<?php $arr = Array ( 0 => Array ( 0 => 'Red', 1 => 'Steel' ), 1 => Array ( 0 => 'Red', 1 => 'Wood' ) , 2 => Array ( 0 => 'Blue', 1 => 'Wood' ) ); $colors = array_unique(array_column($arr, 0)); $materials = array_unique(array_column($arr, 1)); print_r($colors);print_r($materials);

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