Counter Javascript

let counterDisplayElem = document.querySelector('.counter-display');
let counterMinusElem = document.querySelector('.counter-minus');
let counterPlusElem = document.querySelector('.counter-plus');

let count = 0;

updateDisplay();

counterPlusElem.addEventListener("click", () => {
  count++;
  updateDisplay();
});

counterMinusElem.addEventListener("click", () => {
  count--;
  updateDisplay();
});

function updateDisplay() {
  counterDisplayElem.innerHTML = count;
}

<h1 class="counterdisplay">(..)</h1>
<button class="counter-minus">-</button>
<button class="counter-plus">+</button>