是否可以将键索引插入到文件数组中

I am trying to insert a key index to FILE array. I just want to know that is this work in FILE array or not ?

$files = $_FILES;
print_r($files);
Array
(
    [image] => Array
        (
                    [name] => 400.png
                    [type] => image/png
                    [tmp_name] => /tmp/php5Wx0aJ
                    [error] => 0
                    [size] => 15726
        )
)

what i want is like this below:

$files = $_FILES;
print_r($files);
Array
(
    [image] => Array
        (
                    [name] => 400.png
                    [type] => image/png
                    [tmp_name] => /tmp/php5Wx0aJ
                    [error] => 0
                    [size] => 15726
                    [myid]=> my value
        )
)

Is it possible to push key index into $_FILE array with the PHP function?

Yes, you can do it as follows:

$files['image']['myid'] = 'my value';

IIRC, the 'image' key to the $_FILES array is the name of the control in your HTML, if you were just looking for a way to identify which of multiple files is which.