How would I make only one tab open at a time in this accordion? - accordion

Question

The original accordion is from the W3schools site. https://www.w3schools.com/howto/howto_js_accordion.asp.
I am trying to figure out how to only have one tab open a time? Any help would be greatly appreciated. Thanks.
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";
}
});
}

Answer 1

Answering my own question.
var acc = document.getElementsByClassName("accordion");
var i;
for (i = 0; i < acc.length; i++) {
acc[i].addEventListener("click", function() {
var elems = document.getElementsByClassName("accordion");
for(var it of elems) {
it.classList.remove("active");
it.nextElementSibling.style.maxHeight = null;
}
this.classList.toggle("active");
var panel = this.nextElementSibling;
if (panel.style.maxHeight){
panel.style.maxHeight = null;
} else {
panel.style.maxHeight = panel.scrollHeight + "px";
this.nextUntil().addClass( "close" );
}
});
}