I'm trying to do something trivial and running into a problem. When retrieving the checked attribute of a checkbox, I'm getting undefined and I can't figure out why. What am I doing wrong?
console.log($("#invert").attr("checked"));
<input type="checkbox" id="invert"/> Invert Image
Because the element in question doesn't have a checked attribute. It has a checked property though:
console.log($("#invert").prop("checked")); // true or false
Here's a working example.
PROPERTY AND ATTRIBUTE AGAIN.Use prop() instead attr() in 1.9.1
DEMO --> http://jsfiddle.net/YPYME/2/
You're using jQuery 1.9 which uses the latest "prop" property instead of "attr" property which has been deprecated. Lower your jQuery version to < 1.6 or use ".prop".
.attr() method has not been deprecated. It just returns undefined for attributes which do not exist on the element (in 1.6 and below it sometimes used property values instead of attribute values).