Show / hide HTML element

<button onclick="toggleElem(event)">hide</button>
<div style="height: 100px; width: 100px; background-color: red;" id="block"></div>
<script>
  function toggleElem(e) {
    if (e.target.innerText != "show") {
      document.querySelector("#block").style.display = "none";
      e.target.innerText = "show";
    } else {
      document.querySelector("#block").style.display = "block";
      e.target.innerText = "hide";
    }
  }
</script>