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<!DOCTYPE html> <html> <body> <p>Click the button to find out if the button element has an onclick attribute.</p> <button id="myBtn" onclick="myFunction()">Try it</button> <p>Internet Explorer 8 and earlier does not support the hasAttribute() method.</p> <p id="demo"></p> <script> function myFunction() { var x = document.getElementById("myBtn").hasAttribute("onclick"); document.getElementById("demo").innerHTML = x; } </script> </body> </html>