<!DOCTYPE html>
<html>
<body>
<head>
<meta name="description" content="Free Web tutorials">
<meta name="keywords" content="HTML5,CSS,JavaScript">
<meta name="author" content="John Doe">
</head>
<p>Click the button to return the value of the content attribute of all meta elements.</p>
<button onclick="myFunction()">Try it</button>
<p id="demo"></p>
<script>
function myFunction() {
var x = document.getElementsByTagName("META");
var txt = "";
var i;
for (i = 0; i < x.length; i++) {
txt = txt + "Content of "+(i+1)+". meta tag: "+x[i].content+"<br>";
}
document.getElementById("demo").innerHTML = txt;
}
</script>
</body>
</html>