JAVASCRIPT

onclick prevent default

function sayHello(e) {
   e.preventDefault();
   alert("hello");
}
---------------------
 <a href="#" onclick="sayHello(event);">Click to say Hello</a>

onclick prevent default

<a href="#" onclick="event.preventDefault(); myfunc({a:1, b:2});" />click</a>

button prevent default

const handleClick = (event: React.FormEvent<HTMLFormElement>) => {
        event.preventDefault()
        event.stopPropagation()
        console.log('Clicked')
    }

    return (
	         <button onClick={handleClick}>
             	Button text
             </button>
             )