Answers for "jQuery('#id').ready(function(){ jQuery('#id2').show() });"

jquery document ready

The .ready() method is typically used with an anonymous function:
$( document ).ready(function() {
  // Handler for .ready() called.
});

Which is equivalent to the recommended way of calling:
$(function() {
  // Handler for .ready() called.
});

jquery doc on ready

$(document).ready(() => {
	console.log('ready');
});