PHP two-dimensional array to verify whether a value exists

PHP determines whether the number is in a two-dimensional array
$arr = array( <br> array('a', 'b'), <br> array('c', 'd') <br> ); <br> ​ <br> in_array('a', $arr); // What is returned at this time is always false <br> deep_in_array('a', $arr); // Returns true value at this time <br> ​ <br> function deep_in_array($value, $array) { <br> foreach($array as $item) { <br> If(!is_array($item)) { <br>                 if ($item == $value)                                                                                                                                                                                                                                                          return true; } Else {s                                                                                continue;                                                                                                                                                                                                  If(in_array($value, $item)) { <br> Return true;             } else if(deep_in_array($value, $item)) {                                                                               Return true;           } <br>  } <br> Return false; <br> }<br> <br><br><br><br> <br>