About jQuery append() and how to check if an element has been appended

Question

I made a very simple button click event handler, I would like to have

element be appended when button clicked, you can check my code

Answer 1

How to check if an element exists:

if($("p#other").length > 0) {
    // a p element with id "other" exists
}
else {
    // a p element with id "other" does not exist
}