[javascript] jQuery see if any or no checkboxes are selected

I know how to see if an individual checkbox is selected or not.

But Im having trouble with the following - given a form id I need to see if any of the checkboxes are selected (i.e 1 or more), and I need to see if none are selected. Basically I need two separate functions that answer these two questions. Help would be appreciated. Thanks!

Actually, I would just need a function to tell me if none are selected. Knowing this would answer the other question.

Without using 'length' you can do it like this:

if ($('input[type=checkbox]').is(":checked")) {
      //any one is checked
}
else {
//none is checked
}

This is the best way to solve this problem.

  if($("#checkbox").is(":checked")){

  // Do something here /////

  };

JQuery .is will test all specified elements and return true if at least one of them matches selector:

if ($(":checkbox[name='choices']", form).is(":checked"))
{
    // one or more checked
}
else
{
    // nothing checked
}

You can do a simple return of the .length here:

function areAnyChecked(formID) {
  return !!$('#'+formID+' input[type=checkbox]:checked').length;
}

This look for checkboxes in the given form, sees if any are :checked and returns true if they are (since the length would be 0 otherwise). To make it a bit clearer, here's the non boolean converted version:

function howManyAreChecked(formID) {
  return $('#'+formID+' input[type=checkbox]:checked').length;
}

This would return a count of how many were checked.

This is what I used for checking if any checkboxes in a list of checkboxes had changed:

$('input[type="checkbox"]').change(function(){ 

        var itemName = $('select option:selected').text();  

         //Do something.

});     

Rahul's answer is best fit for your question. Anyway, if you have a group of checkboxes to be checked and not all the checkbox in your form, you can go for it.

Put a classname for all the checkboxes you want to check, say for example, a classname test_check and now you can check if any of the checkbox is checked belonging to the group by:

$("#formID .test_check:checked").length > 0

If it returns true, assume that one or more checkboxes are checked having the classname test_check and none checked if returns false.

Hope it helps someone. Thanks :)-

You can do this:

  if ($('#form_id :checkbox:checked').length > 0){
    // one or more checkboxes are checked
  }
  else{
   // no checkboxes are checked
  }

Where:

• :checkbox filter selector selects all checkbox.
• :checked will select checked checkboxes
• length will give the number of checked ones there