Count Specific Values in Multidimensional Array

Counting Values in Multidimensional Array

This can be done with a simple iteration:

$counts = array();
foreach ($array as $key=>$subarr) {
  // Add to the current group count if it exists
  if (isset($counts[$subarr['group']]) {
    $counts[$subarr['group']]++;
  }
  // or initialize to 1 if it doesn't exist
  else $counts[$subarr['group']] = 1;

  // Or the ternary one-liner version 
  // instead of the preceding if/else block
  $counts[$subarr['group']] = isset($counts[$subarr['group']]) ? $counts[$subarr['group']]++ : 1;
}

Update for PHP 5.5

In PHP 5.5, which has added the array_column() function to aggregate an inner key from a 2D array, this can be simplified to:

$counts = array_count_values(array_flip(array_column($array, 'group')));

Count specific values in multidimensional array

$number_of_green_fruit = 0;
for ($row = 0; $row < 3; $row++) {
    if($fruit[$row]["color"]=="green") {
         $number_of_green_fruit++;
         echo $fruit[$row]["name"] . '<br />';
    }
}

Counting Values in Multidimensional Array PHP

You can simply use array_count_values along with call_user_func_array like as

array_count_values(call_user_func_array('array_merge', $array));

PHP: Count and display the value of a multidimensional array

Simple enough here is an example:

<?php

/*Create the array for example */
$data[0]['city'] = "LONDON";
$data[0]['country'] = "ENGLAND";
$data[1]['city'] = "LONDON";
$data[1]['country'] = "ENGLAND";
$data[2]['city'] = "LONDON";
$data[2]['country'] = "ENGLAND";
$data[3]['city'] = "PARIS";
$data[3]['country'] = "FRANCE";
$data[4]['city'] = "LIVERPOOL";
$data[4]['country'] = "ENGLAND";
$data[5]['city'] = "ROME";
$data[5]['country'] = "ITALY";
$data[6]['city'] = "ROME";
$data[6]['country'] = "ITALY";
$data[7]['city'] = "PARIS";
$data[7]['country'] = "FRANCE";
$data[8]['city'] = "BRISTOL";
$data[8]['country'] = "ENGLAND";

/* print the array for show 
echo '<pre>';
print_r($data);*/

foreach($data as $val){
    if(!isset($newData[$val['country']][$val['city']])){
        $newData[$val['country']][$val['city']] = 1;
    } else {
        ++$newData[$val['country']][$val['city']];
    }
    $sorted["{$val['country']} - {$val['city']}"] = $newData[$val['country']][$val['city']];
}

/* print created array */
echo '<pre>';
print_r($newData);

/* print the sorted array */
arsort($sorted);
print_r($sorted);

Will return:

Array
(
    [ENGLAND] => Array
        (
            [LONDON] => 3
            [LIVERPOOL] => 1
            [BRISTOL] => 1
        )

    [FRANCE] => Array
        (
            [PARIS] => 2
        )

    [ITALY] => Array
        (
            [ROME] => 2
        )

)
Array
(
    [ENGLAND - LONDON] => 3
    [FRANCE - PARIS] => 2
    [ITALY - ROME] => 2
    [ENGLAND - LIVERPOOL] => 1
    [ENGLAND - BRISTOL] => 1
)

Edit - Added select from $newData:

Example of select - just to illustrate how to loop and get your values and keys:

?><select id="city" name="city"><?php
foreach($newData as $country => $cities){
    
    foreach($cities as $city => $quantity){
        ?>
          <option id="<?php echo $city;?>" value='<?php echo "$country-$city";?>' ><?php echo $city;?></option>
       <?php
    }
    
}
?></select><?php

Will return:

Sample Image

Which is:

<select id="city" name="city">        
    <option id="LONDON" value="ENGLAND-LONDON">LONDON</option>    
    <option id="LIVERPOOL" value="ENGLAND-LIVERPOOL">LIVERPOOL</option>    
    <option id="BRISTOL" value="ENGLAND-BRISTOL">BRISTOL</option>   
    <option id="PARIS" value="FRANCE-PARIS">PARIS</option>  
    <option id="ROME" value="ITALY-ROME">ROME</option>
</select>

Edit - if you want this: all data sorted and countries

Sample Image
Do this:

add

$sorted2[$val['city']] = $newData[$val['country']][$val['city']];
$countries[$val['city']] = $val['country'];

to the first foreach after $sorted...

after the loop add:

arsort($sorted2);

And in the select loop do this:

?><select id="city" name="city"><?php
foreach($sorted2 as $city => $quantity){
        ?>
            <option id="<?php echo $city;?>" value='<?php echo $city;?>' ><?php echo "$city $countries[$city] ($quantity)";?></option>
        <?php
}
?></select><?php

How to count all values in a multidimensional array?

Since your array is not flattened, you will need to visit each value and increment unless you want to call merging functions.

Code: (Demo)

$array = [
    1 => [1, 12, 2],
    2 => [1, 13, 3],
    3 => [1, 12, 2],
    4 => [1],
    5 => [1]
];

//           make the generated value available outside of function scope
//           \-------------------------------v--------------------------/
array_walk_recursive($array, function($v)use(&$output) {  // visit each leafnode
    if (isset($output[$v])) {  // check if the key has occurred before
        ++$output[$v];         // increment
    } else {
        $output[$v] = 1;       // declare as 1 on first occurrence
    }
});

var_export($output);

Output:

array (
  1 => 5,
  12 => 2,
  2 => 2,
  13 => 1,
  3 => 1,
)

Or, non-recursively:

foreach ($array as $row) {
    foreach ($row as $v) {
        if (isset($output[$v])) { // check if the key has occurred before
            ++$output[$v];        // increment
        } else {
            $output[$v] = 1;      // declare as 1 on first occurrence
        }
    }
}

Or, a functional one-liner to flatten then count:

var_export(array_count_values(array_reduce($array, 'array_merge', array())));

Or, a functional one-liner with the splat operator to flatten then count:

var_export(array_count_values(array_merge(...$array)));

How to count occurrence of values in multidimensional array in php

You can try to loop then check if year key and month key already exist

$group = [];
foreach ($array as $value) {
    $month = $value[1][0];
    if (!isset($group[$value[0]])) {
        $group[$value[0]] = array('count' => 0);
    }
    if (!isset($group[$value[0]][$month])) {
        $group[$value[0]][$month] = 0;
    }
    $group[$value[0]][$month] += 1;
    $group[$value[0]]['count'] += 1;
}

print_r($group);

If you don't necessarily need the count, you can change the first if condition's execution to $group[$value[0]] = array(); and the line $group[$value[0]]['count'] += 1;

foreach ($array as $value) {
    $month = $value[1][0];
    if (!isset($group[$value[0]])) {
        $group[$value[0]] = array();
    }
    if (!isset($group[$value[0]][$month])) {
        $group[$value[0]][$month] = 0;
    }
    $group[$value[0]][$month] += 1;
}

print_r($group);

PHP: Return count of some values in multidimensional array but retain other values i.e id

A properly constructed foreach loop will do the trick. When a name is first found, set it as a key, and declare a default subarray for it (id and count = 0). Then just increment the count value for every occurrence.