This will be much more complex than that as file arrays can be nested, eg:

```html
<p>file1:<input type="file" name="photo[]"></p>
<p>file2:<input type="file" name="photo[]"></p>
<p>file3:<input type="file" name="photo[][]"></p>
<p>file4:<input type="file" name="photo[][]"></p>
<p>file5:<input type="file" name="photo[][][]"></p>
<p>file6:<input type="file" name="photo[][][][][]"></p>
```