Javascript question: How do I duplicate user input

Question

How can I pass input from a text-type input element into a hidden input element in the same form on a site that has jquery installed?

Answer 1

$("#id_of_hidden_input").val($("#id_of_text_input").val());

Answer 2

Assuming that you have only one field of each type:

$('input[type=hidden]').val($('input[type=text]').val())

If you have more add IDs to selectors

Answer 3

If input_1 is the id of the input you want to populate, and input_2 the id you want to populate from, use:

$("#input_1").val($("#input_2").val())

Answer 4

Triggered when the text changes:

$("#text_id").change(function(){
  $("#hidden_id").val($("#text_id").val())
});

Triggered when the form submits:

$("#form_id").submit(function(){
  $("#hidden_id").val($("#text_id").val())
});

Check out other jQuery Events.