Close navbar when clicked outside and not just the close button

Question

I got this working version of Navigation to open from the right side of the screen. It closes when I click on the close button.

I would like it to close when I click outside of the navbar too and just restrict it to the close button X. How should I proceed with that?

function openNav() {
    document.getElementById("mySidenav").style.width = "250px";
}

function closeNav() {
    document.getElementById("mySidenav").style.width = "0";
}

.sidenav {
    height: 100%;
    width: 0;
    position: fixed;
    z-index: 1;
    top: 0;
    right: 0;
    background-color: #111;
    overflow-x: hidden;
    transition: 0.5s;
    padding-top: 60px;
}

.sidenav a {
    padding: 8px 8px 8px 32px;
    text-decoration: none;
    font-size: 25px;
    color: #818181;
    display: block;
    transition: 0.3s;
}

.sidenav a:hover, .offcanvas a:focus{
    color: #f1f1f1;
}

.sidenav .closebtn {
    position: absolute;
    top: 0;
    right: 25px;
    font-size: 36px;
    margin-left: 50px;
}

@media screen and (max-height: 450px) {
  .sidenav {padding-top: 15px;}
  .sidenav a {font-size: 18px;}
}

<div id="mySidenav" class="sidenav">
  <a href="javascript:void(0)" class="closebtn" onclick="closeNav()">&times;</a>
  <a href="#">About</a>
  <a href="#">Services</a>
  <a href="#">Clients</a>
  <a href="#">Contact</a>
</div>

<h2>Animated Sidenav Example</h2>
<p>Click on the element below to open the side navigation menu.</p>
<span style="font-size:30px;cursor:pointer" onclick="openNav()">&#9776; open</span>

Answer 1

try this

function openNav() {
    document.getElementById("mySidenav").style.width = "250px";
}

function closeNav() {
    document.getElementById("mySidenav").style.width = "0";
}

$('body').on('click', function(){
  if( parseInt( $('#mySidenav').css('width') ) > 0 ){
    closeNav();
  }
});

.sidenav {
    height: 100%;
    width: 0;
    position: fixed;
    z-index: 1;
    top: 0;
    right: 0;
    background-color: #111;
    overflow-x: hidden;
    transition: 0.5s;
    padding-top: 60px;
}

.sidenav a {
    padding: 8px 8px 8px 32px;
    text-decoration: none;
    font-size: 25px;
    color: #818181;
    display: block;
    transition: 0.3s;
}

.sidenav a:hover, .offcanvas a:focus{
    color: #f1f1f1;
}

.sidenav .closebtn {
    position: absolute;
    top: 0;
    right: 25px;
    font-size: 36px;
    margin-left: 50px;
}

@media screen and (max-height: 450px) {
  .sidenav {padding-top: 15px;}
  .sidenav a {font-size: 18px;}
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div id="mySidenav" class="sidenav">
  <a href="javascript:void(0)" class="closebtn" onclick="closeNav()">&times;</a>
  <a href="#">About</a>
  <a href="#">Services</a>
  <a href="#">Clients</a>
  <a href="#">Contact</a>
</div>

<h2>Animated Sidenav Example</h2>
<p>Click on the element below to open the side navigation menu.</p>
<span style="font-size:30px;cursor:pointer" onclick="openNav()">&#9776; open</span>

Answer 2

You could add a click event listener to window, so if the user clicks anywhere the menu closes. If you don't want it to close if the user clicks an item in the menu, use

event.stopPropagation()

function openNav() {
    document.getElementById("mySidenav").style.width = "250px";

    window.addEventListener(
        "click",
        closeNav
    );
}

function closeNav() {
    document.getElementById("mySidenav").style.width = "0";
    window.removeEventListener("click", closeNav);
}