Determine number of Dimensions in a PHP Array

Is there a way to determine how many dimensions there are in a PHP array开发者_C百科?

Nice problem, here is a solution I stole from the PHP Manual:

function countdim($array)
{
    if (is_array(reset($array)))
    {
        $return = countdim(reset($array)) + 1;
    }

    else
    {
        $return = 1;
    }

    return $return;
}

you can try this:

$a["one"]["two"]["three"]="1";

function count_dimension($Array, $count = 0) {
   if(is_array($Array)) {
      return count_dimension(current($Array), ++$count);
   } else {
      return $count;
   }
}

print count_dimension($a);

Like most procedural and object-oriented languages, PHP does NOT natively implement multi-dimensional arrays - it uses nested arrays.

The recursive function suggested by others are messy, but the nearest thing to an answer.

C.

This one works for arrays where each dimension doesn't have the same type of elements. It may need to traverse all elements.

$a[0] = 1;
$a[1][0] = 1;
$a[2][1][0] = 1;

function array_max_depth($array, $depth = 0) {
    $max_sub_depth = 0;
    foreach (array_filter($array, 'is_array') as $subarray) {
        $max_sub_depth = max(
            $max_sub_depth,
            array_max_depth($subarray, $depth + 1)
        );
    }
    return $max_sub_depth + $depth;
}

Here's a solution that worked for me to get the number of dimensions of an arrays that is not evenly distributed.

function count_dimension($array, $count = 0) {
$maxcount = 0;
foreach ($array as $key) {
    if(is_array($key)) {
        $count = count_dimension(current($key), ++$count);
        if($count > $maxcount) {
            $maxcount = $count;
        }
    } else {
        if($count > $maxcount) {
            $maxcount = $count;
        }
    }
}

return $maxcount;}

You could use the following single-line statement to differentiate between 1-D and 2-D arrays

if (gettype(reset($array)) == "array")

This returns true for a 2-D array and a false for a 1-D array.

was corrected at Some issues with jumping from one function to another in a loop in php

This double function will go to the last dimension of each array in $a and when its not an array anymore it will echo the number of loops it did to get there with a delimiter |. The downside of this code is it only echoes and cannot be returned (in normal way).

function cc($b, $n)
{
    $n++.' ';
    countdim($b, $n);

}
function countdim($a, $n = 0)
{
    if(is_array($a))
    {
        foreach($a as $b)
        {
            cc($b, $n);
        }
    }else
    {
        echo $n.'|';
    }
}
countdim($a);

Here i made a function with return, but.. its a return from html then "GET" back to php on button click.. I dont know any other way to make it work.. so just name your array to $a and hit the button :/

$max_depth_var = isset($_REQUEST['max_depth_var']) ? $_REQUEST['max_depth_var'] : 0;
?>
<form id="form01" method="GET">
<input type="hidden" name="max_depth_var" value="<?php
function cc($b, $n)
{
    $n++.' ';
    bb($b, $n);
}
function bb($a, $n = 0)
{
    if(is_array($a))
    { 
        foreach($a as $b)cc($b, $n); 
    }else
    {
    echo $n.', ';
    };
}
bb($a); ?>">
<input type="submit" form="form01" value="Get max depth value">
</form><?php
$max_depth_var = max(explode(', ', rtrim($max_depth_var, ",")));
echo "Array's maximum dimention is $max_depth_var.";

If only the innermost array has items, you can use the following function:

function array_dim($array = []) {
    $dim = 0;
    $json = json_encode($array);
    $json_last_index = strlen($json) - 1;

    while (in_array($json[$json_last_index - $dim], ['}', ']'])) {
        $dim++;
    }

    return $dim;
}

If you want to calculate the maximum array dimension you can use the following function:

function max_array_dim($array = []) {
    $json = json_encode($array);

    $step = 0;
    $max = 0;
    for ($i = 0; $i < strlen($json); $i++) {
        if (in_array($json[$i], ['[', '{'])) {
            $step++;
        }
        if (in_array($json[$i], [']', '}'])) {
            $step--;
        }
        $max = max($max, $step);
    }

    return $max;
}