jquery toggleClass not working

You just need to toggle class for the current clicked link, and before that, remove active and focus class for all links, like this:

$('a.btn').click(function(){
  $("a.btn").removeClass("active focus");
  $(this).toggleClass("active");
});

a.active {
  color: red;
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<a id="single" class="btn active">single</a>
<a id="double" class="btn">double</a>

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