Click anywhere to close side navbar javascript

Question

I am using below snippet within bootstrap to display a sidebar in the navigation bar.

I am able to close the navbar by clicking on the X button in the sidebar. How can I change my closeNav javascript to be able to close the sidebar by clicking anywhere on the page well as the close button using javascript only?

function openNav() {
    document.getElementById("mySidenav").style.width = "230px";
    document.getElementById("main").style.marginLeft = "250px";
}

/* Set the width of the side navigation to 0 and the left margin of the page content to 0 */
function closeNav() {
  document.getElementById("mySidenav").style.width = "0";
  document.getElementById("main").style.marginLeft = "0";
}
  

/* The side navigation menu */
.sidenav {
    height: 100%; /* 100% Full-height */
    width: 0; /* 0 width - change this with JavaScript */
    position: fixed; /* Stay in place */
    z-index: 1; /* Stay on top */
    top: 0;
    left: 0;
    background-color: #111; /* Black*/
    overflow-x: hidden; /* Disable horizontal scroll */
    padding-top: 60px; /* Place content 60px from the top */
    transition: 0.5s; /* 0.5 second transition effect to slide in the sidenav */
}

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

/* When you mouse over the navigation links, change their color */
.sidenav a:hover, .offcanvas a:focus{
    color: #f1f1f1;
}

/* Position and style the close button (top right corner) */
.sidenav .closebtn {
    position: absolute;
    top: 0;
    right: 25px;
    font-size: 36px;
    margin-left: 50px;
}

/* Style page content - use this if you want to push the page content to the right when you open the side navigation */
#main {
    transition: margin-left .5s;
    padding: 20px;
}

/* On smaller screens, where height is less than 450px, change the style of the sidenav (less padding and a smaller font size) */
@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>

<!-- Use any element to open the sidenav -->
<span onclick="openNav()">Siderbar Button click here</span>

<div id="main">
Body content is here</div>

Answer 1

First things first. I would recommend you not to use at all onclick property in HTML, that's why eventlisteners were created

document.querySelector('span#open_menu').addEventListener('click', openNav)

document.querySelector('.closebtn').addEventListener('click', closeNav)

Second, simply add another event listener to your #main div in the same way, have in mind you can trigger the same event with different elements with no problem at all

document.querySelector('#main').addEventListener('click', closeNav)

Remember to use always event listeners and never JS within the HTML!

Answer 2

Just add an event listener to the div:

document.getElementById('main').addEventListener('click', closeNav);

function openNav() {
  document.getElementById("mySidenav").style.width = "230px";
  document.getElementById("main").style.marginLeft = "250px";
}

/* Set the width of the side navigation to 0 and the left margin of the page content to 0 */
function closeNav() {
  document.getElementById("mySidenav").style.width = "0";
  document.getElementById("main").style.marginLeft = "0";
}

/* The side navigation menu */

.sidenav {
  height: 100%;
  /* 100% Full-height */
  width: 0;
  /* 0 width - change this with JavaScript */
  position: fixed;
  /* Stay in place */
  z-index: 1;
  /* Stay on top */
  top: 0;
  left: 0;
  background-color: #111;
  /* Black*/
  overflow-x: hidden;
  /* Disable horizontal scroll */
  padding-top: 60px;
  /* Place content 60px from the top */
  transition: 0.5s;
  /* 0.5 second transition effect to slide in the sidenav */
}


/* The navigation menu links */

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


/* When you mouse over the navigation links, change their color */

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


/* Position and style the close button (top right corner) */

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


/* Style page content - use this if you want to push the page content to the right when you open the side navigation */

#main {
  transition: margin-left .5s;
  padding: 20px;
}


/* On smaller screens, where height is less than 450px, change the style of the sidenav (less padding and a smaller font size) */

@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>

<!-- Use any element to open the sidenav -->
<span onclick="openNav()">Siderbar Button click here</span>

<div id="main" style="height:100vh;">
  Body content is here
</div>