i am trying to toggle classes by using class name.
My code is working fine when i am toggling using id.
how can i make it work only one red should be visible at one time.
function hideshowmenu() {
var element = document.getElementsByClassName("box");
element.classList.toggle("bg-red");
}.bg-red {
margin-top: 10px;
background-color: red;
height: 20px;
}<div class="mainmenu " onclick="hideshowmenu()">RED1</div>
<div id="submenu" class="submenu">
<div class="mainmenu " onclick="hideshowmenu()">RED2</div>
<div id="box" class="box"> </div>
</div>As the name of getElementsByClassName suggest, it returns elementS, so you are getting HTMLCollection, not one element. Query the first one, like this:
function hideshowmenu() {
var element = document.getElementsByClassName("box")[0];
element.classList.toggle("bg-red");
}
or:
function hideshowmenu() {
var elements = document.getElementsByClassName("box");
elements[0].classList.toggle("bg-red");
}
What is returned by document.getElementsByClassName("box"); is a collection. You need to specify the index to access the classList property.
You are doing:
var element = document.getElementsByClassName("box");
element.classList.toggle("bg-red");
When you should be doing
var element = document.getElementsByClassName("box");
element[0].classList.toggle("bg-red");
You could also loop through the elements if you want to toggle multiple values.
Example code fiddle https://jsfiddle.net/agy5jtb0/1/
getElementsByClassName("box") return a collection of elements, but you considered it as a single element that is your mistake.
I suggest something like this:
html:
<div class="mainmenu " onclick="hideshowmenu(this)">RED1</div>
<div id="submenu" class="submenu">
<div class="mainmenu" onclick="hideshowmenu(this)">RED2</div>
<div id="box" class="box"></div>
</div>
js:
function hideshowmenu(el) {
el.classList.toggle("bg-red");
}