Tryit Editor v2.9

Edit This Code:
<!DOCTYPE html>
<html>
<head>
<style>
div {
    border: 1px solid black;
    margin: 5px;
}
</style>
</head>
<body>

<p>Click the button to find out how many children the div element below has.</p>

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

<div id="myDIV">
  <p>First p element (index 0)</p>
  <p>Second p element (index 1)</p>
</div>

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

<script>
function myFunction() {
    var c = document.getElementById("myDIV").children.length;
    document.getElementById("demo").innerHTML = c;
}
</script>

</body>
</html>