Question

How do I link the file input type with the checkbox?

This is what I have so far:

<input type="file" name="file_upload[0]"  /> <input type="checkbox" name="checkbox[0]"> checkbox 1 <br />
<input type="file" name="file_upload[1]"  /> <input type="checkbox" name="checkbox[1]"> checkbox 2 <br />
<input type="file" name="file_upload[2]"  /> <input type="checkbox" name="checkbox[2]"> checkbox 3 <br />
<input type="file" name="file_upload[3]"  /> <input type="checkbox" name="checkbox[3]"> checkbox 4 <br />

Now I need to check in PHP when a file is uploaded the correspondent checkbox is checked (preferably with a loop), but I can’t make it work.

This is what I have in PHP:

if (isset($_FILES['file_upload[1]']) && isset($_FILES['checkbox[1]']))  {
    //do something
} else {
    //do something else
}

Answer 1

You need to change your checkbox input tag to <input type="checkbox" name="checkbox[3]" value="1" >

i.e. you need to add missing value="" attribute

and as mentioned in the comment

you need to check if(isset($_POST['checkbox'][0])) { instead in $_FILES

Try printing both print_r($_FILES) and print_r($_POST) … this should give you idea of what structure of data you are receiving after submitting

You can just loop through the file_uploaded array and then check if related checbox index is set.