<div class="container-fluid">
  <div class="row" id="row-main">
    <div class="col-md-3" id="sidebar">  
    </div>
    <div class="col-md-9" id="content">
      <button type="button" class="btn btn-default toggle-sidebar">Toggle sidebar</button>
    </div>
  </div>
</div>
#row-main {
  overflow-x: hidden;
}
#content, #sidebar {
  height: 100vh;
}
#content {
  background-color: lightblue;
  -webkit-transition: width 0.3s ease;
  -moz-transition: width 0.3s ease;
  -o-transition: width 0.3s ease;
  transition: width 0.3s ease;
}
#sidebar {
  background-color: gray;
  -webkit-transition: margin 0.3s ease;
  -moz-transition: margin 0.3s ease;
  -o-transition: margin 0.3s ease;
  transition: margin 0.3s ease;
}
.collapsed {
  margin-left: -25%;
}
button {
  margin-top: 10px;
}
$(document).ready(function() {
  $(".toggle-sidebar").click(function() {
  $("#sidebar").toggleClass("collapsed");
  $("#content").toggleClass("col-md-12 col-md-9");
  });
});

External CSS

  1. https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/4.0.0-beta/css/bootstrap.min.css

External JavaScript

  1. https://cdnjs.cloudflare.com/ajax/libs/jquery/3.2.1/jquery.min.js