Add / Remove Classes

<p id="highlightText">Click the button to highlight me!</p>
<button id="addBtn">Add Highlight</button>
<button id="removeBtn">Remove Highlight</button>

<style>
.highlight {
  background-color: yellow;
  font-weight: bold;
}
</style>

<script>
$(document).ready(function(){
  $("#addBtn").click(function(){
$("#highlightText").addClass("highlight");
  });

  $("#removeBtn").click(function(){
$("#highlightText").removeClass("highlight");
  });
});
</script>

.addClass() → Adds CSS class.
.removeClass() → Removes CSS class.