php返回第一个元素的数组键？

Question

I have an assoc array in PHP which I am sorting by value. After sorting I need to return the key of the first element.

Example array:

Array
(
    [a] => 42.857142857143
    [b] => 87.5
    [c] => 50
    [d] => 61.538461538462
)

Then I use asort(), and the array looks like this:

Array
(
    [b] => 87.5
    [d] => 61.538461538462
    [c] => 50
    [a] => 42.857142857143
)

How can I return "b" (as it is the key of the first array)?

Answer 1

You can use key() in combination with reset() to make sure you have the first element:

reset($arr);
$key = key($arr);