Detect a CheckBox's Checked Status in JavaScript or jQuery

Checkboxes are an important part of forms, and knowing whether they are checked, in JavaScirpt and jQuery, can be very useful.

Standard checking in JavaScript is very simple...

console.log("Checked status?" + document.getElementById('MyCheckBox').checked);

Checking in jQuery is similarly not very difficult...

console.log("Checked status?" + $('#MyCheckBox').is(":checked"));

If you have a newer version of jQuery (v. 1.6+), the following will also work...

console.log("Checked status?" + $('#MyCheckBox').prop('checked'));

Make sure not to mix these up, or you will get bad results. jQuery selectors return an array of matched elements. If you try to look at $('#MyCheckBox').checked, you will always see false, whereas $('#MyCheckBox')[0].checked would be more likely to work.