Re: [PHP] Need routine to tell me number of dimensions in array.

On 15 March 2010 23:45, Daevid Vincent <[email protected]> wrote:
> Anyone have a function that will return an integer of the number of
> dimensions an array has?

/**
 * Get the maximum depth of an array
 *
 * @param array &$Data A reference to the data array
 * @return int The maximum number of levels in the array.
 */
function arrayGetDepth(array &$Data) {
	static $CurrentDepth = 1;
	static $MaxDepth = 1;

	array_walk($Data, function($Value, $Key) use(&$CurrentDepth, &$MaxDepth) {
		if (is_array($Value)) {
			$MaxDepth = max($MaxDepth, ++$CurrentDepth);
			arrayGetDepth($Value);
			--$CurrentDepth;
		}
	});

	return $MaxDepth;
}

Extending Jim and Roberts comments to this. No globals. By using a
reference to the array, large arrays are not copied (memory footprint
is smaller). And by using array_walk, a separate internal pointer is
used, so no need to worry about losing your position on the array.

Something to watch out for though is recursion in the array. If a
value in the array is a reference to another part of the array, you
are going to loop around for ever.

$Data = array(&$Data);

for example, with the line ...

		echo "$CurrentDepth, $MaxDepth, $Key\n";

in the callback function() will report 17701 before crashing out (no
stack error surprisingly enough).


Regards,

Richard Quadling.


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