On click dropdown if window width is less than 600

Question

I am new to JS.

I am trying to toggle between adding a bit of CSS code to existing CSS by doing this (I think this is JQuery).

$('#navIt').click(function () {

    $('#navIt').addClass('.drop', $(window).width() < 600);

}, function () {
    $('#navIt').removeClass('.drop', $(window).width() < 600);
});

I don't know if this is the correct code. I found this from here and here , but it doesn't seem to work for me.

Html

<div id="navIt" class="nav">
    <ul>
        <li class="current"><a>Portfolio</a></li>
        <li><a>Illustration</a></li>
        <li><a>Web Design</a></li>
        <li><a>Print Media</a></li>
        <li><a>Graphic Design</a></li>
    </ul>
</div>

CSS

/* nav */
.nav {
    position: relative;
    margin: 20px 0;
}
.nav ul {
    margin: 0;
    padding: 0;
}
.nav li {
    margin: 0 5px 10px 0;
    padding: 0;
    list-style: none;
    display: inline-block;
}
.nav a {
    padding: 3px 12px;
    text-decoration: none;
    color: #999;
    line-height: 100%;
}
.nav a:hover {
    color: #000;
}
.nav .current a {
    background: #999;
    color: #fff;
    border-radius: 5px;
}

/* right nav */
.nav.right ul {
    text-align: right;
}

/* center nav */
.nav.center ul {
    text-align: center;
}
@media screen and (max-width: 600px) {
    .nav {
        position: relative;
        min-height: 40px;
    }
    .nav ul {
        width: 180px;
        padding: 5px 0;
        position: absolute;
        top: 0;
        left: 0;
        border: solid 1px #aaa;
        background: #fff url(images/icon-menu.png) no-repeat 10px 11px;
        border-radius: 5px;
        box-shadow: 0 1px 2px rgba(0,0,0,.3);
    }
    .nav li {
        display: none; /* hide all <li> items */
        margin: 0;
    }
    .nav .current {
        display: block; /* show only current <li> item */
    }
    .nav a {
        display: block;
        padding: 5px 5px 5px 32px;
        text-align: left;
    }
    .nav .current a {
        background: none;
        color: #666;
    }

    /* right nav */
    .nav.right ul {
        left: auto;
        right: 0;
    }

    /* center nav */
    .nav.center ul {
        left: 50%;
        margin-left: -90px;
    }

}

@media screen and (max-width: 600px) {
    /*on click hover */
    .drop ul {
        background-image: none;
    }

    .drop ul li {
        display: block;
        margin: 0 0 5px;
    }

    .drop ul .current {
        background: url(images/icon-check.png) no-repeat 10px 7px;
    }
}

In the end, what I want to do is that, if the window size is less than 600, I should be able to toggle between .drop class.

Any idea on how to do it?

Answer 1

Add or remove it like this, with simple if/else

$('#navIt').click(function () {
  if($(window).width() < 600){
     $(this).addClass('drop');
  }

  else{
    $(this).removeClass('drop');
  }

});

Answer 2

See .addClass() for reference: https://api.jquery.com/addclass/

An example which should make it clear: https://jsfiddle.net/wdof7fxt/

Just resize your browser window and you'll see the square turn red/white. Tweak it for your needs.

JavaScript

$(window).on('resize', function() {
  if($(this).width() > 600) {
    $('#box').css('background-color', 'white');
  }
  else {
    $('#box').css('background-color', 'red');
  }
});