event listeners on in[it code example

Example 1: event listener javascript

//DOM Level 2 Event Listener (Advanced technique to call an event)
document.getElementById("btn2").addEventListener('click', () => {
    alert("hello world");
}, false);
//our third param of DOM Level 2 Event Listener
// false = event trigger from bottom to top(bubbling phase)
// true = event trigger from top to bottom (capturing phase)


//TRADITIONAL DOM EVENT HANDLERS (very old)
function show_alert() {
    alert("hello world");
}
document.getElementById("btn1").onclick = show_alert;

Example 2: event listener javascript

document.querySelector('div').addEventListener('click', () => {
  console.log('div clicked');
});