Question

I used to write this:

$('#MyDiv .TheClass').eq(TheIndex).removeClass('ClassA');
$('#MyDiv .TheClass').eq(TheIndex).removeClass('ClassB');
$('#MyDiv .TheClass').eq(TheIndex).addClass('ClassC');

$('#MyDiv .TheClass').eq(TheIndex).children().each(function () {
 //do something here
});

and now I’m writing this:

$('#MyDiv .TheClass').eq(TheIndex)
  .removeClass('ClassA ClassB')
  .addClass('ClassC')
  .children().each(function () { 
      // do something here
  });

Is the latter going to run faster than the former? Just curious.

Answer 1

One thing’s for sure, this codes FINDS the element each line:

$('#MyDiv .TheClass').eq(TheIndex).removeClass('ClassA');
$('#MyDiv .TheClass').eq(TheIndex).removeClass('ClassB');
$('#MyDiv .TheClass').eq(TheIndex).addClass('ClassC');

In chaining, if finding the element is just once, it is faster then:

$('#MyDiv .TheClass').eq(TheIndex)
  .removeClass('ClassA ClassB')
  .addClass('ClassC')
  .children().each(function () { 
  // do something here
});