Tryit Editor v2.7

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

<script>
var _hmt = _hmt || [];
(function() {
var hm = document.createElement("script");
hm.src = "//hm.baidu.com/hm.js?73c27e26f610eb3c9f3feb0c75b03925";
var s = document.getElementsByTagName("script")[0];
s.parentNode.insertBefore(hm, s);
})();
</script>
</head>
<body>

<div id="myDIV">
  <p>First p element in div.</p>
  <p>Another p element in div.</p>
  <p>A third p element in div.</p>
</div>

<p>Click the button to find out how many p elements there are inside the div element.</p>

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

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

<script>
function myFunction() {
    var div = document.getElementById("myDIV");
    var nodelist = div.getElementsByTagName("P");
    document.getElementById("demo").innerHTML = nodelist.length;
}
</script>

</body>
</html>