Question

I want to validate my form having

<input type="file" id="file[]">

I want to submit form only when file is uploaded else throw an error message popup.
The problem is this that i have made the code to upload the multiple files. So ID attribute of <input type="file"> is array(file[]).

I have tried

1. document.getElementById('file').value
2. document.getElementById('file[]').value
3. document.getElementById('file[3]').value

But everytime it’s not working.
I have checked it via firebug, it is giving error

 document.getElementById(...) // is null.

Answer 1

You cannot create multiple elements with same id. Instead of id use class=’fileInput’ and
Use

var fileArr = document.getElementByClassName(“fileInput”) ;

Then loop through the array and check whether all the file input is valid..