Show alert when a button click for second time in javaScript

Question

I have a button and I want to show an alert when user click on the button for second time. Actually I want to disable second click on a button and show error alert !

How can I do this with JavaScript ?

Answer 1

Having this button in your HTML

<button onclick="whichClick()">Click me</button>

You can add a class on your first click and then check is the class is already present, so you can throw the error:

function whichClick(e) {
    if (e.target.className.contains('clicked')) {
       alert("error");
    } else {
       e.target.className.addClass('clicked');
    }
}