如何按键对子阵列进行排序？

I Have array like this.

[PT. Bersinar Terang] => Array
(
    [2017] => Array
    (
        [0] => Array
        (
            [id] => 12
            [nama_perusahaan] => PT. Bersinar Terang
        )
    )

    [2016] => Array
    (
        [0] => Array
        (
            [id] => 16
            [nama_perusahaan] => PT. Bersinar Terang
        )
    )
)

How can I sort ascending by years? Thanks For help.

You can use ksort. Here is the code.

ksort($arr['PT. Bersinar Terang']);

For more information, check this link.

Use ksort() function

ksort($arr['PT. Bersinar Terang']);
print_r($arr);exit;

DEMO