Php recursive array counting

Question

I'm trying to write a function which counts array elements recursively.

But result is false.

What could it be problem?

$schema = array(
    'div' => array(
        'class' => 'lines',
        'div' => array(
             'span' => array(
                'key' => 'Product Name'
            ),
            'val' => 'Soap'
        ),
        'layer' => array(
             'span' => array(
                'key' => 'Product Name'
            ),
            'val' => 'Ball'
            )
        )
);

function count_r($array, $i = 0){
    foreach($array as $k){
        if(is_array($k)){ $i += count_r($k, count($k)); }
        else{ $i++; }
    }
    return $i;
}

echo count_r($schema);

False or zero? Run var_dump($schema) and tell us the output. — Connor Peet
– Connor Peet, Commented Aug 25, 2013 at 14:24
Ah, that is quite different. Why do you have count_r($k, count($k));? Shouldn't need the second argument. — Connor Peet
– Connor Peet, Commented Aug 25, 2013 at 14:26

Christian P · Accepted Answer · 2023-09-28 18:11:56Z

46

There is a built-in function in PHP that you can use: count().

This is how you can use it:

count($schema, COUNT_RECURSIVE);

This function also detects recursion to avoid infinite loops so it's safer than solutions in other answers.

edited Sep 28, 2023 at 18:11

answered Feb 6, 2014 at 14:06

Christian P

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1 Comment

xarlymg89 Over a year ago

This should be the proper solution, since as @Christian P says, PHP has a built in method to accomplish this. And it's simply using the 'count' function. count($multi_level_array, COUNT_RECURSIVE)

Sorin Gheata · Accepted Answer · 2015-03-16 16:09:02Z

14

PHP has a built-in method for this purpose, called count(). If passed without any additional parameters, count() returns the number of array keys on the first level. But, if you pass a second parameter to the count method count( $schema, true ), then the result will be the total number of keys in the multi-dimensional array. The response marked as correct only iterates first and second level arrays, if you have a third child in that array, it will not return the correct answer.

This could be written as a recursive function, if you really want to write your own count() method, though.

answered Mar 16, 2015 at 16:09

Sorin Gheata

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Comments

Mithun Satheesh · Accepted Answer · 2013-08-25 14:36:43Z

1

your function could be simple as

function count_r($array, $i = 0){
    foreach($array as $k){
        $i++;
        if(is_array($k)){ 
            $i += count_r($k); 
        }
    }
    return $i;
}

answered Aug 25, 2013 at 14:36

Mithun Satheesh

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Comments

stubben · Accepted Answer · 2018-11-19 09:26:29Z

1

If you want to count specific keys/values you can use the built-in array_walk_recursive with a closure function.

$schema = array(
    'div' => array(
        'class' => 'lines',
        'div' => array(
             'span' => array(
                'key' => 'Product Name'
            ),
            'val' => 'Soap'
        ),
        'layer' => array(
             'span' => array(
                'key' => 'Product Name'
            ),
            'val' => 'Ball'
            )
        )
);

$elements = 0;
array_walk_recursive($schema, function($value, $key) use (&$elements) {
  if (strstr($value, 'Product')) $elements++;
});

print $elements; // 2

/*
Values
  lines
  Product Name
  Soap
  Product Name
  Ball

Keys
  class
  key
  val
  key
  val
*/

answered Nov 19, 2018 at 9:26

stubben

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1 Comment

mickmackusa Over a year ago

This is the correct answer to a different question.

mickmackusa · Accepted Answer · 2021-04-09 03:54:55Z

Transferred from comment below answer:

Basically, as you're adding the count_r of that array to the current level, you don't need to factor in the count in the second argument - you'd basically be adding it twice. You need the "1" in there, however, to count the array itself. If you'd want to count just the elements and not the arrays, you would just make the "1" a "0".

$schema = array(
    'div' => array(
        'class' => 'lines',
        'div' => array(
             'span' => array(
                'key' => 'Product Name'
            ),
            'val' => 'Soap'
        ),
        'layer' => array(
             'span' => array(
                'key' => 'Product Name'
            ),
            'val' => 'Ball'
            )
        )
);

function count_r($array, $i = 0){
    foreach($array as $k){
        if(is_array($k)){ $i += count_r($k, 1); }
        else{ $i++; }
    }
    return $i;
}

echo count_r($schema);

This is tested and works correctly.

Manivasagan · Accepted Answer · 2013-08-25 14:39:33Z

0

I have altered you code.. Please check it. It is working fine.

$schema = array(
'div' => array(
    'class' => 'lines',
    'div' => array(
         'span' => array(
            'key' => 'Product Name'
        ),
        'val' => 'Soap'
    ),
    'layer' => array(
         'span' => array(
            'key' => 'Product Name'
        ),
        'val' => 'Ball'
        )
    )

);

function count_r($array){
 foreach($array as $k){
    if(is_array($k)){
            $i += count_r($k); 
        }
    else{
        $i++; 
    }
}
return $i;

} echo count_r($schema);

answered Aug 25, 2013 at 14:39

Manivasagan

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Comments

soma · Accepted Answer · 2022-11-02 10:42:28Z

0

count($array, COUNT_RECURSIVE)-count($array)

answered Nov 2, 2022 at 10:42

soma

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2 Comments

mickmackusa Over a year ago

Why have you dumped this unexplained code here? This is not a high quality answer. Why do you recommend it? What does it do? How does it work? Why is it better than all previous answers? Please edit your post.

Tomato Over a year ago

If I understand correctly how count works, this is valid as far as you only have array of dimension equal 2 (and the values you want to count only in the deepest level - the second dimension). It will recursively count all keys and subtracts keys in first dimension making it count of keys in second dimension.

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