Check if element exists in jQuery

$('elemId').length doesn't work for me.

You need to put # before element id:

$('#elemId').length
---^

---

With vanilla JavaScript, you don't need the hash (#) e.g. document.getElementById('id_here') , however when using jQuery, you do need to put hash to target elements based on id just like CSS.

Try to check the length of the selector, if it returns you something then the element must exists else not.

 if( $('#selector').length )         // use this if you are using id to check
{
     // it exists
}


 if( $('.selector').length )         // use this if you are using class to check
{
     // it exists
}

Try this:

if ($("#mydiv").length > 0){
  // do something here
}

The length property will return zero if element does not exists.