Is there a way to find out how "deep" a PHP array is?

php arrays associative-array
Thomas Owens picture Thomas Owens · Nov 4, 2008 · Viewed 45.1k times · Source

A PHP array can have arrays for its elements. And those arrays can have arrays and so on and so forth. Is there a way to find out the maximum nesting that exists in a PHP array? An example would be a function that returns 1 if the initial array does not have arrays as elements, 2 if at least one element is an array, and so on.

Answer

Jeremy Ruten picture Jeremy Ruten · Nov 4, 2008

Here's another alternative that avoids the problem Kent Fredric pointed out. It gives print_r() the task of checking for infinite recursion (which it does well) and uses the indentation in the output to find the depth of the array.

function array_depth($array) {
    $max_indentation = 1;

    $array_str = print_r($array, true);
    $lines = explode("\n", $array_str);

    foreach ($lines as $line) {
        $indentation = (strlen($line) - strlen(ltrim($line))) / 4;

        if ($indentation > $max_indentation) {
            $max_indentation = $indentation;
        }
    }

    return ceil(($max_indentation - 1) / 2) + 1;
}

Related questions

In PHP, how do you change the key of an array element?

I have an associative array in the form key => value where key is a numerical value, however it is not a sequential numerical value. The key is actually an ID number and the value is a count. This is …

Read More
Adding an item to an associative array

//go through each question foreach($file_data as $value) { //separate the string by pipes and place in variables list($category, $question) = explode('|', $value); //place in assoc array $data = array($category => $question); print_r($data); } This is not …

Read More
Display array values in PHP

So, I'm working with PHP for the first time and I am trying to retrieve and display the values of an array. After a lot of googling, the only methods I can find for this are print_r, var_dump …

Read More