I am trying to determine the top offset of an element and the console logs an error, even though JQuery's documentation says it should be written like this:
$('.myObject').offset().top
Error:
Uncaught TypeError: Cannot read property 'top' of undefined
Why does this happen? Any solution for the problem?
This usually happens because $('.myObject') returns nothing. To protect your code from crashing, check if the element exists before calling .offset().top
var myObj = $('.myObject');
if (myObj.length){
myObj.offset().top
}
Since .top is a property and not a method, it is not handled by jQuery and, hence, will crash your script if it is not existing.
var myObject= $('.myObject'); and then use myObject. This prevents jQuery from having to traverse the DOM twice, which is relatively very expensive.
You'll have to check if the element exists.
e.g.
var myObjExists = $('.myObject').length > 0 ? true : false;
if you then console.log(myObjExists);, it should return true or false.
From here you can do some errorhandling to why it does not exist.
If you need more details, please also post the HTML that this code points to.
$('#myObject')? Using a class selector may be returning a set instead of one element.