How to check if an element exists on the page with jQuery?

To check if an element exists on the page with jQuery, you can use the length property of the jQuery object returned by selecting the element. Here is an example:

if ($("#elementId").length) {
  // Element with the given id exists on the page
} else {
  // Element with the given id does not exist on the page
}

This code checks if an element with the id "elementId" exists on the page using the $("#elementId") selector. If the length property is greater than 0, it means the element exists.