when do we use keypress listener in javascript code example

Example 1: keypress javascript

The keypress event has been deprecated, 
you should look to use beforeinput : https://developer.mozilla.org/en-US/docs/Web/API/HTMLElement/beforeinput_event
or keydown : https://developer.mozilla.org/en-US/docs/Web/API/Document/keydown_event
instead.

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Example 2: how do i listen to a keypress in javascript

let b = document.getElementById("body"); //making var for body
b.addEventListener("keydown", (evt) => {//when this happens
	console.log(evt.keyCode); //log keycode
});

Example 3: adding event listener keypress event in javascript

let msg = document.getDocumentById('#message');

msg.addEventListener("keydown", (event) => {
    // handle keydown
});

msg.addEventListener("keypress", (event) => {
    // handle keypress
});

msg.addEventListener("keyup", (event) => {
    // handle keyup
});