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<?php function getAllCombinationsArray(){ $return = array(); $root = array( 1=>'cat1', 2=>'cat2', 3=>'cat3' ); $child_1 = array( 1=>'sub_cat1', 2=>'sub_cat2', 3=>'sub_cat3' ); $child_2 = array( 1=>'sub_sub_cat1', 2=>'sub_sub_cat2', 3=>'sub_sub_cat3' ); foreach($root as $fk => $fv){ foreach($child_1 as $ck => $cv){ $cid = $fk.'_'.$ck; $cname = $fv.' -> '.$cv; foreach($child_2 as $ck2 => $cv2){ $id = $cid.'_'.$ck2; $name = $cname.' -> '.$cv2; $return[$id] = $name; } } } return $return; } print_r(getAllCombinationsArray());

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