Setting the value of checkbox to true or false with jQuery

I have a form with a checkbox. With jQuery I would like to set the value of the checkbox to TRUE if checked, and if it is not checked, the value will be set to FALSE. How I can do this please?

You can do (jQuery 1.6 onwards):

$('#idCheckbox').prop('checked', true);
$('#idCheckbox').prop('checked', false);

to remove you can also use:

$('#idCheckbox').removeProp('checked');

with jQuery < 1.6 you must do

$('#idCheckbox').attr('checked', true);
$('#idCheckbox').removeAttr('checked');

UPDATED: Using prop instead of attr

 <input type="checkbox" name="vehicle" id="vehicleChkBox" value="FALSE"/>

 $('#vehicleChkBox').change(function(){
     cb = $(this);
     cb.val(cb.prop('checked'));
 });

OUT OF DATE:

Here is the jsfiddle

<input type="checkbox" name="vehicle" id="vehicleChkBox" value="FALSE" />
    
$('#vehicleChkBox').change(function(){
     if($(this).attr('checked')){
          $(this).val('TRUE');
     }else{
          $(this).val('FALSE');
     }
});

Use $('#id-of-the-checkbox').prop('checked', true_or_false);

In case you are using an ancient jQuery version, you'll need to use .attr('checked', 'checked') to check and .removeAttr('checked') to uncheck.

Try this:

HTML:

<input type="checkbox" value="FALSE" />

jQ:

$("input[type='checkbox']").on('change', function(){
  $(this).val(this.checked ? "TRUE" : "FALSE");
})

jsfiddle

Please bear in mind that unchecked checkbox will not be submitted in regular form, and you should use hidden filed in order to do it.

var checkbox = $( "#checkbox" );
checkbox.val( checkbox[0].checked ? "true" : "false" );

This will set the value of the checkbox to "true" or "false" (value property is a string), depending whether it's unchecked or checked.

Works in jQuery >= 1.0

<input type="checkbox" name="vehicle" id="vehicleChkBox" value="FALSE"/>

--

$('#vehicleChkBox').change(function(){
    if(this.checked)
        $('#vehicleChkBox').val('TRUE');
   else
        $('#vehicleChkBox').val('False');
});