合併多個數組，然後按數組值排序

Question

請幫助我，我需要合併多個數組，然後按數組值排序。下面的問題是：

$array1 = array("abc", "def", "ghi", "jkl", "mno"); 
$array2 = array("mno", "jkl", "mno", "ghi", "pqr", "stu"); 
$array3 = array_merge($array1, $array2); 
$array4 = ??? 

print_r($array4); 

我想要的$array4回報這樣的：

Array 
(
[0] => mno 
[1] => ghi 
[2] => jkl 
[3] => abc 
[4] => def 
[5] => pqr 
[6] => stu 
) 

Answer 1

你可以這樣做：

$array1 = array("abc", "def", "ghi", "jkl", "mno"); 
$array2 = array("mno", "jkl", "mno", "ghi", "pqr", "stu"); 
$array3 = array_merge($array1, $array2); 

// get the array of count. 
$array4 = array_count_values($array3); 

// sort it in reverse order. 
arsort($array4); 

// extract just the keys. 
$array4 = array_keys($array4); 

Working example