The getAttribute() method gives you the specified attribute name of an element.
element.getAttribute (attributename)
Let's say I have an < h3 > element, "Age". getAttribute() retrieves the value of my "Age":
var x = document.getElementsByTagName("H1")[0].getAttribute("class");
Click the button to display the value of the class attribute of the h3 element "Age".
We can also use getAttribute() to retrieve the value of an < a > element:
var x = document.getElementById("myAnchor").getAttribute("target");
Check out my CSS drawings.
Click the button to display the value of the target attribute of the link up there.
Getting the value of the onclick event attribute of a < button > element:
var x = document.getElementById("butt").getAttribute("onclick");
Click the button to display the value of the onclick attribute of the button element.