How can I get form data with JavaScript/jQuery?

$('form').serialize() //this produces: "foo=1&bar=xxx&this=hi"

demo

Updated answer for 2014: HTML5 FormData does this

var formData = new FormData(document.querySelector('form'))

You can then post formData exactly as it is - it contains all names and values used in the form.

Use $('form').serializeArray(), which returns an array:

[
  {"name":"foo","value":"1"},
  {"name":"bar","value":"xxx"},
  {"name":"this","value":"hi"}
]

Other option is $('form').serialize(), which returns a string:

"foo=1&bar=xxx&this=hi"

Take a look at this jsfiddle demo