Checking if array is multidimensional or not?

Question

1. What is the most efficient way to check if an array is a flat array of primitive values or if it is a multidimensional array?

Answer 1

In addition to the previous answers and depending on the schema of the array you want to check:

function is_multi_array($array=[],$mode='every_key'){

    $result = false;

    if(is_array($array)){

        if($mode=='first_key_only'){

            if(is_array(array_shift($array))){

                $result = true;
            }
        }
        elseif($mode=='every_key'){

            $result = true;

            foreach($array as $key => $value){

                if(!is_array($value)){

                    $result = false;
                    break;
                }
            }
        }
        elseif($mode=='at_least_one_key'){

            if(count($array)!==count($array, COUNT_RECURSIVE)){

                $result = true; 
            }
        }
    }

    return $result;
}