将数组值翻转到数组键的功能？

Question

是否有一个PHP函数可以采取以下数组

array (size=4)
 1 => string '0' 
 6 => string '1' 
 7 => string '1' 
 8 => string '7' 

并将其翻转到下面的数组注意,数组必须具有唯一键值,因此我们可以翻转数组,其中值1 =键值6,7

array (size=3)
 0 => string '1' 
 1 => string '6, 7'
 7 => string '8' 

Answer 1

$arr = array ( 1 => '0', 6 => '1', 7 => '1', 8 => '7' );

// Find unique values of array and make them as keys
$res = array_flip($arr);
// Find keys from sourse array with value of key in new array
foreach($res as $k =>$v) $res[$k] = implode(", ", array_keys($arr, $k));

结果

Array
(
    [0] => 1
    [1] => 6, 7
    [7] => 8
)