基于重复元素的数量对PHP中的多维关联数组进行排序/限制

Question

I have a multi-dimensional array in PHP as follows:

$array = Array ( 
        [0] => Array ( [bill] => 1 ) 
        [1] => Array ( [bill] => 1 ) 
        [2] => Array ( [bill] => 1 ) 
        [3] => Array ( [bill] => 1 )        
        [4] => Array ( [jack] => 5 ) 
        [5] => Array ( [jack] => 5 ) 
        [6] => Array ( [jake] => 6 ) 
        [7] => Array ( [jake] => 6 ) 
        [8] => Array ( [jake] => 6 ) 
        [9] => Array ( [jake] => 6 ) 
        [10] => Array ( [sara] => 7 ) 
        [11] => Array ( [sara] => 7 ) 
        [12] => Array ( [sara] => 7 ) 
        [13] => Array ( [sara] => 7 ) 
        [14] => Array ( [william] => 8 ) 
        [15] => Array ( [william] => 8 ) 
        [16] => Array ( [william] => 8 ) 
        [17] => Array ( [william] => 8 ) 
        [19] => Array ( [william] => 8 ) 
        [20] => Array ( [martin] => 9 ) 
        [21] => Array ( [martin] => 9 ) 
        [22] => Array ( [martin] => 9 ) 
        [23] => Array ( [tara] => 10 ) 
        [24] => Array ( [tara] => 10 ) 
        [25] => Array ( [tara] => 10 )              
        [26] => Array ( [tara] => 10 )              
      );

I want to convert $array to $result so that it can first sort the array based on the number of similar elements and then returning the first five values. For example, the $array has five similar [william] => 8, four similar [bill] => 1, four similar [jake] => 6, four similar [sara] => 7, four similar [tara] => 10, three similar [martin] => 9 and two similar [jack] => 5 in $array variable. So, the $result variable with the first five most repeated elements should be as follows:

$result = Array (
        [0] => Array ( [william] => 8 ) 
        [1] => Array ( [bill] => 1 ) 
        [2] => Array ( [jake] => 6 ) 
        [3] => Array ( [sara] => 7 ) 
        [4] => Array ( [tara] => 10 ) 
      );

Could you please help me how to solve this problem?

Answer 1

Create a new array that combines the keys and values and use array_count_values to count the # of occurrences. Finally sort and retrieve the top 5.

$new = array();      

foreach($array as $key => $value) {
    $new[] = key($value) . '_' . current($value);
}

$counts = array_count_values($new);
arsort($counts);
$results = array();

foreach(array_splice($counts,0,5) as $key => $count) {
    $key = explode('_',$key);
    $results[] = array($key[0] => $key[1]);
}

print_r($results);