File value is undefined in jQuery click

In my project, all forms are similar to each other, so I want to write one click function to run all.

Following code works fine except files. File value outputs as undefined. How can I attach file to this form data?

Here's my click function:

$("#save_form").click(
    function(event){
        event.preventDefault();

        var formData = {};

        $('.form-value').each(function() {
            var id = $(this).attr('id');
            var value;
            if ($(this).is('select')) {
                value = $(this).find('option:selected').val();
            } else if ($(this).is(':file')) {
                value = $(this)[0].files[0].value; // Returns undefined.
            } else {
                value = $(this).val();
            }
            formData[id] = value;
        });

        console.log(formData);

When I use without value:

value = $(this)[0].files[0]

I get:

Uncaught TypeError: Illegal invocation

Just use the file itself. Files do not have a value property.

value = this.files[0];

To send the FormData with jQuery.ajax, add the options processData: false and contentType: false to prevent jQuery from trying to convert the FormData.

With the help of David and Unmitigated, I solved the issue.

• I send file, not the value.

  value = $(this)[0].files[0];
  

• And than, I added two lines to ajax (processData and contentType as false)

  method: 'POST',
  data: formData,
  processData: false, 
  contentType: false,