Change the Background of all Elements in a Class

Question

I have a div, when I clicked on it, should turn all the elements in the .counter class to red, but at the moment it does nothing. I believe you have to run through a loop first

Answer 1

   function handleClick() {
   var myCounters = document.getElementsByClassName("counter")
   for (var i = 0; i < myCounters.length; i++) {
    myCounters[i].style.backgroundColor = "red"
   }

}

.counter {
  width: 100px;
  height: 100px;
  background-color: orange;
}

#btn {
  background-color: aqua;
  width: 50px;
  height: 50px;
  position: absolute;
  left: 200px;
  top: 10px;
}