Question

I am using the following code to remove an element from the DOM tree:

 function onItemDeleted(name) {

           $("#" + name).remove();                       

       }

Would this be bad for performance since I am not indicating any parent for the element. The element is a TR contained in a TABLE element. The DOM search for this element will start at the top which might be BODY. So would it be something like this:

BODY => DIV => TABLE => TR (found)

If I find the parent of TR which is TABLE would the search be like this:

TABLE -> TR

I don’t know if above will be true since I think search will always start at the root node.

Answer 1

jQuery optimises for ID searches. So, $("#" + name) is effectively the same as $(document.getElementById(name)). From the source, line 120 (1.4):

// HANDLE: $("#id")
} else {
    elem = document.getElementById( match[2] );