Complete DOM Property code

<p id="demo">   This element has extra spacing   and contains <span>a span element</span>.</p>

<button onclick="getInnerText()">Get innerText</button>
<button onclick="getHTML()">Get innerHTML</button>
<button onclick="getTextContent()">Get textContent</button>

<p id="demo"></p>

<script>
function getInnerText() {
  alert(document.getElementById("demo").innerText)
}

function getHTML() {
  alert(document.getElementById("demo").innerHTML)
}

function getTextContent() {
  alert(document.getElementById("demo").textContent)
}
</script>