Toggle Class Active with JQuery On Scroll

Question

I am trying to toggle active class in the nav links while scrolling and here's my code :

$(function () {
    "use strict";
$(window).on("scroll", function (event) {
        var $scrollPos = $(document).scrollTop(),
            $links = $('.nav ul li a');
        $links.each(function () {
            var $currLink = $(this),
                $refElement = $($currLink.attr("href"));
            if ($refElement.position().top <= $scrollPos && $refElement.position().top + $refElement.height() > $scrollPos) {
                $links.removeClass("active");
                $currLink.addClass("active");
            } else {
                $currLink.removeClass("active");
            }
        });
    });
});

.nav {
  background-color:#222;
  padding:15px 10px;
  position:fixed;
  top:0;
  left:0;
  width:100%;
}
.nav ul li {
  display:inline;
  margin:0 20px;
}
.nav ul li a {
  text-decoration:none;
  color:#fff;
}
.active {
  color:red;
}
#home,#about,#services,#contact {
  height:600px;
}
h1 {
  text-align:center;
  font-size:30px;
  padding:100px 0;
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>
<div class="nav">
    <ul>
        <li><a href="#home" class="smoothScroll">Home</a></li>
        <li><a href="#about" class="smoothScroll">About</a></li>
        <li><a href="#services" class="smoothScroll">Services</a></li>
        <li><a href="#contact" class="smoothScroll">Contact</a></li>
    </ul>
</div>

<div id="home"> <h1>Home</h1> </div>
<div id="about"> <h1>about</h1> </div>
<div id="services"> <h1>services</h1> </div>
<div id="contact"> <h1>contact</h1> </div>

But something went wrong and it doesn't work - maybe someone can help me find out where's my wrong.

Answer 1

Use .nav ul li a.active instead of .active because .nav ul li a is more specific style than .active - see demo below:

$(function () {
    "use strict";
$(window).on("scroll", function (event) {
        var $scrollPos = $(document).scrollTop(),
            $links = $('.nav ul li a');
        $links.each(function () {
            var $currLink = $(this),
                $refElement = $($currLink.attr("href"));
            if ($refElement.position().top <= $scrollPos && $refElement.position().top + $refElement.height() > $scrollPos) {
                $links.removeClass("active");
                $currLink.addClass("active");
            } else {
                $currLink.removeClass("active");
            }
        });
    });
});

.nav {
  background-color:#222;
  padding:15px 10px;
  position:fixed;
  top:0;
  left:0;
  width:100%;
}
.nav ul li {
  display:inline;
  margin:0 20px;
}
.nav ul li a {
  text-decoration:none;
  color:#fff;
}
.nav ul li a.active {
  color:red;
}
#home,#about,#services,#contact {
  height:600px;
}
h1 {
  text-align:center;
  font-size:30px;
  padding:100px 0;
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>
<div class="nav">
    <ul>
        <li><a href="#home" class="smoothScroll">Home</a></li>
        <li><a href="#about" class="smoothScroll">About</a></li>
        <li><a href="#services" class="smoothScroll">Services</a></li>
        <li><a href="#contact" class="smoothScroll">Contact</a></li>
    </ul>
</div>

<div id="home"> <h1>Home</h1> </div>
<div id="about"> <h1>about</h1> </div>
<div id="services"> <h1>services</h1> </div>
<div id="contact"> <h1>contact</h1> </div>

Answer 2

use this in your css instead of only .active:

.nav ul li a.active {
    color:red;
}

OR you can use !important like this :

.active {
    color:red!important;
}

But be careful, read this subject