How to modify Hide/Show button for class instead of ID

I have found this code for a hide/show ID effect. I am building with Elementor in WP.

<button onclick="myFunction()">show / hide</button>

function myFunction() {
  var x = document.getElementById ("showprice");
  if (x.style.display === "none") {
    x.style.display = "block";
  } else {
    x.style.display = "none";
  }
} 

This works, but I would like to modify the code to hide/show a Class instead of ID – but changing it to the following doesn’t work. Any tips?

function myFunction() {
  var x = document.getElementsByClassName("showprice");
  if (x.style.display === "none") {
    x.style.display = "block";
  } else {
    x.style.display = "none";
  }
}