With jQuery/JavaScript Is it slower to declare variables that will only be used once?

I just want to make sure I understand this basic idea correctly, and no matter how I phrase it, I'm not coming up with completely relevant search results. This is faster: function () { $('#someID').someMethod( $('#someOtherID').data('some-data') ); } than this: function () { var variableOne = $('#someID'), variableTwo = $('#someIDsomeOtherID').data('some-data'); variableOne.someMethod( variableTwo ); } is that correct? I think the question may be "Is declaring variables slower than not declaring variables?" :facepalm: The particular case where I questioned this is running a similarly constructed function after an AJAX call where some events must be delegated on to the newly loaded elements.