I am learning html/css and learned accordion menu 2 days ago. But I want to do the same thing in reverse. In other words, the menus will be open at startup, when I click on the title, they will collapse. Unfortunately I was never able to do that. Does anyone have an idea?
var acc = document.getElementsByClassName("accordion");
var i;
for (i = 0; i < acc.length; i++) {
acc[i].addEventListener("click", function() {
this.classList.toggle("active");
var panel = this.nextElementSibling;
if (panel.style.maxHeight) {
panel.style.maxHeight = null
} else {
panel.style.maxHeight = panel.scrollHeight + "px";
}
});
}.accordion {
background-color: #FFFFFF;
cursor: pointer;
padding: 18px;
width: 100%;
border: none;
text-align: left;
font-size: 15px;
}
.accordion:after {
content: "\002B";
/* plus sign */
font-weight: bold;
float: right;
margin-left: 5px;
}
.active:after {
content: "\2212";
}
/* minus sign */
.panel {
padding: 0 18px;
max-height: 0;
overflow: hidden;
transition: max-height 0.2s ease-out;
}<table width="750">
<td style="width: 100%;">
<button class="accordion">Header 1</button>
<div class="panel">
<p>Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor</p>
</div>
<button class="accordion">Header 2</button>
<div class="panel">
<p>Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor</p>
</div>
<button class="accordion">Header 3</button>
<div class="panel">
<p>Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor</p>
</div>
</td>
</table>Simple add manually active on accordion button and style="max-height: 50px;" to panel
var acc = document.getElementsByClassName("accordion");
var i;
for (i = 0; i < acc.length; i++) {
acc[i].addEventListener("click", function() {
this.classList.toggle("active");
var panel = this.nextElementSibling;
if (panel.style.maxHeight) {
panel.style.maxHeight = null
} else {
panel.style.maxHeight = panel.scrollHeight + "px";
}
});
}.accordion {
background-color: #FFFFFF;
cursor: pointer;
padding: 18px;
width: 100%;
border: none;
text-align: left;
font-size: 15px;
}
.accordion:after {
content: "\002B";
/* plus sign */
font-weight: bold;
float: right;
margin-left: 5px;
}
.active:after {
content: "\2212";
}
/* minus sign */
.panel {
padding: 0 18px;
max-height: 0;
overflow: hidden;
transition: max-height 0.2s ease-out;
}<table width="750">
<td style="width: 100%;">
<button class="accordion active">Header 1</button>
<div class="panel" style="max-height: 50px;">
<p>Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor</p>
</div>
<button class="accordion active">Header 2</button>
<div class="panel" style="max-height: 50px;">
<p>Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor</p>
</div>
<button class="accordion active">Header 3</button>
<div class="panel" style="max-height: 50px;">
<p>Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor</p>
</div>
</td>
</table>