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I am trying to have the class of each elements change one at a time in sequence automatically. This means element 1 glows then goes off as element 2 glows and then goes off and so on. When each element has glowed once the whole sequence starts over.

$('header div:first').toggleClass('highlight').nextAll().toggleClass('none');

function highlight() {
  var $off = $('header div.highlight').toggleClass('none');

  if ($off.next().length) {
    $off.next().toggleClass('none');
  } else {
    $off.prevAll().last().toggleClass('highlight');
  }
}

$(document).ready(function() {
  setInterval(highlight, 1000);
});

<script src=".1.1/jquery.min.js"></script>
<header>
 <div>element 1</div>
 <div>element 2</div>
 <div>element 3</div>
 <div>element 4</div>
</header>

I am trying to have the class of each elements change one at a time in sequence automatically. This means element 1 glows then goes off as element 2 glows and then goes off and so on. When each element has glowed once the whole sequence starts over.

$('header div:first').toggleClass('highlight').nextAll().toggleClass('none');

function highlight() {
  var $off = $('header div.highlight').toggleClass('none');

  if ($off.next().length) {
    $off.next().toggleClass('none');
  } else {
    $off.prevAll().last().toggleClass('highlight');
  }
}

$(document).ready(function() {
  setInterval(highlight, 1000);
});

<script src="https://ajax.googleapis./ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<header>
 <div>element 1</div>
 <div>element 2</div>
 <div>element 3</div>
 <div>element 4</div>
</header>

It wont work as expected (elements 2 through 4 highlight all at the same time and then go off while element 1 doesnt change at all) and I dont know why. What am I doing wrong?

• javascript
• jquery
• toggleclass

Share Improve this question Follow edited May 5, 2016 at 18:52 user2226755 13.2k66 gold badges5353 silver badges7575 bronze badges asked May 5, 2016 at 18:45 Cain NukeCain Nuke 3,10388 gold badges4444 silver badges7676 bronze badges 6

• 1 I think that extra .none is useless. All you need is your .highlight – Roko C. Buljan Commented May 5, 2016 at 18:50
• should I take it off from where? – Cain Nuke Commented May 5, 2016 at 18:52
• 1 Everywhere, unless you include some CSS in your question that demonstrates it has an actual purpose. Just toggle your highlight class instead. – Thernys Commented May 5, 2016 at 18:53
• 1 @RokoC.Buljan "Copy snippet to answer" button saves time – user2226755 Commented May 5, 2016 at 18:57
• @HorsSujet woopsz sorrree :) I see now Good job! – Roko C. Buljan Commented May 5, 2016 at 18:59

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4 Answers 4

Sorted by: Reset to default 5

So yes, you don't need the .none. Simply use your default styles and the .highlight class.
Get the number of items, create a counter, increment it and loop it using % Reminder Operator:

jQuery(function( $ ) { // DOM is ready

  var $el = $("header>div"), tot = $el.length, c = 0;

  $el.eq(c).addClass("highlight"); // initial highlight

  setInterval(function() {
    $el.removeClass("highlight").eq(++c%tot).addClass("highlight");
  }, 1000);

});

header > div           { transition:0.5s; -webkit-transition:0.5s; }
header > div.highlight { color:#f0f; }

<script src="https://ajax.googleapis./ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<header>
 <div>element 1</div>
 <div>element 2</div>
 <div>element 3</div>
 <div>element 4</div>
</header>

Some docs:
https://api.jquery./eq/
https://developer.mozilla/en/docs/Web/JavaScript/Reference/Operators/Arithmetic_Operators#Remainder_()

The none class along with the toggleClass() calls can be a bit confusing to read through. You may be better off by simply keeping track of your current highlighted element via div.highlight and determining which one to target next using the updated code below :

function highlight() {
    // Remove the highlight from all options
    var $current = $('div.highlight');
    // Store the next one
    var $next = $current.next('div');
    // Remove all highlighting
    $('div.highlight').removeClass('highlight')
    if($next.length){
      $next.addClass('highlight');
    } else {
      $('header div:first').addClass('highlight');
    }
}
// When the document is ready
$(function() {
    // Initially set your first element as highlighted and start your interval
    $('header div:first').addClass('highlight');
    setInterval(highlight, 1000);
});

Example

You can see an example of this in action here and demonstrated below :

Image is for example purposes only and timing may appear different than actual code executing... :)

Solution :

Change .none by .highlight, like this :

$('header div:first').toggleClass('highlight');

function highlight() {
  var $off = $('header div.highlight').toggleClass('highlight');

  if ($off.next().length) {
    $off.next().toggleClass('highlight');
  } else {
    $off.prevAll().last().toggleClass('highlight');
  }
}

$(document).ready(function() {
  setInterval(highlight, 1000);
});

.highlight {
   color:red; 
}

<script src="https://ajax.googleapis./ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<header>
 <div>element 1</div>
 <div>element 2</div>
 <div>element 3</div>
 <div>element 4</div>
</header>

Other ways :

$('header div:first').toggleClass('highlight');

setInterval(function() {
  var abc = "highlight";
      $off = $('header div.' + abc),
      $next = $off.next().length ? $off.next() : $off.prevAll().last();

  $off.toggleClass(abc);
  $next.toggleClass(abc);
}, 1000);

.highlight {
   color:red; 
}

<script src="https://ajax.googleapis./ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<header>
 <div>element 1</div>
 <div>element 2</div>
 <div>element 3</div>
 <div>element 4</div>
</header>

You could try this approach.

Javascript

var highlight = function(){
$('header div').removeClass('highlight');
$('header div').each(function(i,v) {
setTimeout(function(){$(v).prev().toggleClass('highlight');$(v).toggleClass('highlight');}, i*1000);
});
setTimeout(highlight, ($('header div').length)*1000);
};
highlight();

Fiddle

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