How to get input type using jquery?

EDIT Feb 1, 2013. Due to the popularity of this answer and the changes to jQuery in version 1.9 (and 2.0) regarding properties and attributes, I added some notes and a fiddle to see how it works when accessing properties/attributes on input, buttons and some selects. The fiddle here: http://jsfiddle.net/pVBU8/1/

get all the inputs:

var allInputs = $(":input");

get all the inputs type:

allInputs.attr('type');

get the values:

allInputs.val();

NOTE: .val() is NOT the same as :checked for those types where that is relevent. use:

.attr("checked");

EDIT Feb 1, 2013 - re: jQuery 1.9 use prop() not attr() as attr will not return proper values for properties that have changed.

.prop('checked');

or simply

$(this).checked;

to get the value of the check - whatever it is currently. or simply use the ':checked' if you want only those that ARE checked.

EDIT: Here is another way to get type:

var allCheckboxes=$('[type=checkbox]');

EDIT2: Note that the form of:

$('input:radio');

is perferred over

$(':radio');

which both equate to:

$('input[type=radio]');

but the "input" is desired so it only gets the inputs and does not use the universal '*" when the form of $(':radio') is used which equates to $('*:radio');

EDIT Aug 19, 2015: preference for the $('input[type=radio]'); should be used as that then allows modern browsers to optimize the search for a radio input.

EDIT Feb 1, 2013 per comment re: select elements @dariomac

$('select').prop("type");

will return either "select-one" or "select-multiple" depending upon the "multiple" attribute and

$('select')[0].type 

returns the same for the first select if it exists. and

($('select')[0]?$('select')[0].type:"howdy") 

will return the type if it exists or "howdy" if it does not.

 $('select').prop('type');

returns the property of the first one in the DOM if it exists or "undefined" if none exist.

$('select').type

returns the type of the first one if it exists or an error if none exist.

You could do the following:

var inputType = $('#inputid').attr('type');

If what you're saying is that you want to get all inputs inside a form that have a value without worrying about the input type, try this:

Example: http://jsfiddle.net/nfLfa/

var $inputs = $('form').find(':checked,:selected,:text,textarea').filter(function() {
    return $.trim( this.value ) != '';
});

Now you should have a set of input elements that have some value.

You can put the values in an array:

var array = $inputs.map(function(){
    return this.value;
}).get();

Or you could serialize them:

var serialized = $inputs.serialize();

GetValue = function(id) {
  var tag = this.tagName;
  var type = this.attr("type");

  if (tag == "input" && (type == "checkbox" || type == "radio"))
    return this.is(":checked");

  return this.val();
};