php - 在键值对中，如何根据value大小得到key的排序？

Question

如：

 $test={"A":1,"B":3,"C":2,"D":1,"E":1};
 

得到：

$result={"B":3,"C":2,"A":1,"D":1,"E":1};

试过rsort($test),不行。
很像sql语句中的orderby,能否有办法？

Answer 1

看看文档

>>> arsort($test)
>>> $test
=> [
     "B" => 3,
     "c" => 2,
     "e" => 1,
     "d" => 1,
     "A" => 1,
   ]

Answer 2

function cmp($a, $b)
{

if ($a == $b) {
    return 0;
}
return ($a < $b) ? -1 : 1;

}

$a = array(3, 2, 5, 6, 1);

usort($a, "cmp");

foreach ($a as $key => $value) {

echo "$key: $value\n";

}

Answer 3

可以看下这个函数 array_multisort