FormData vs .serialize(), What is the difference?

问题

Recently I was submitting a form using AJAX.

In researching the best method I saw some AJAX submissions using .serialize() and others using FormData. For example.

One submission did this:

data: form.serialize()

while the other did:

var formData = new FormData($('form')[0]);
data: formData

So what is the difference between FormData and .serialize()?

回答1:

The main difference from a usage standpoint is that you can't serialize files, only file names....the value of a file input.

FormData object on the other hand also includes files if applicable.

Also serialize() will work in older browsers that don't support the FormData API for example IE < 10

reference FormData docs

回答2:

One more important difference is the treatment of empty input-fields in forms.

serialize()

only contains input-fields with a value. Unchecked check-boxes or empty input-fields will be missing in the key/value pairs. Therefore the backend of your application will have to do some book-keeping in order to interpret missing keys as empty values.

FormData

will get you a complete list of all your form fields and their values. Even if they are empty.

来源：https://stackoverflow.com/questions/33469684/formdata-vs-serialize-what-is-the-difference