Tryit Editor v2.9

Edit This Code:
<!DOCTYPE html>
<html>
<head>
<style>
div {
    border: 1px solid black;
    margin: 15px;
}
</style>
</head>
<body>

<p>Click the button to get the node name of the DIV's first child node.</p>

<div id="myDIV"><p>A P element - First child in div</p><span>A Span element - Last child in div</span></div>

<button onclick="myFunction()">Try it</button>

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

<script>
function myFunction() {
    var x = document.getElementById("myDIV").firstChild.nodeName;
    document.getElementById("demo").innerHTML = x; 
}
</script>

</body>
</html>