.checked=true not working with jquery $ function

Question

hi all...

i want to select a checkbox when a button is clicked.

<form action="" method="post" id="form2">
    <input type="checkbox" id="checkone" value="one" name="one" />
    <input type="button" value="Click me" id="buttonone"/>
</form>

when i tried the following, the checkbox was not getting selected

$('#buttonone').click(function() {
    $('#checkone').checked=true;
});

then i tried:

$('#buttonone').click(function() {
    document.getElementById('checkone').checked=true;
});

this time the checkbox got selected. why isn't it getting selected with the jquery $ function?

Answer 1

Try

$('#checkone').attr('checked', true);

or

$('#checkone').get(0).checked = true;

or

$('#checkone')[0].checked = true; // identical to second example

The reason your first code didn't work is because you were trying to set the checked property on a jQuery object which will have no visible effect as it only works on the native DOM object.

By calling get(0) or accessing the first item [0], we retrieve the native DOM element and can use it normally as in your second example. Alternatively, set the checked attribute using jQuery's attr function which should work too.

Answer 2

Try

$('#checkone').attr('checked', true);

You don't have direct access to DOM object properties because jQuery operates on collections ($(selector) is an array). That's why you have functions defined to manipulate the contents of the returned elements.

Answer 3

You need to use .attr() for the jQuery object, like this:

$('#buttonone').click(function() {
  $('#checkone').attr('checked', true);
});

But it's better to do it the DOM way, like this:

$('#buttonone').click(function() {
  $('#checkone')[0].checked = true; //get the DOM element, .checked is on that
});

Or, completely without jQuery:

document.getElementById('buttonone').onclick = function() {
  document.getElementById('checkone').checked = true;
};

Answer 4

try

$('#checkone').attr('checked', true);

cleary googling for "jquery check a checkbox" was the way to go