The keypress() method triggers the keypress event, or attaches a function to run when a keypress event occurs. The keypress event is similar to the keydown event. The event occurs when a button is pressed down. However, the keypress event is not fired for all keys (e.g. ALT, CTRL, SHIFT, ESC). Use the keydown() method to also check these keys.

Syntax:

$(selector).keypress() - Trigger the keypress event for the selected elements.

$(selector).keypress(function) - Attach a function to the keypress event.

Example:

	<!doctype html>
	<html lang="en">
		<head>
			<meta charset="utf-8">

			<script src="https://code.jquery.com/jquery-3.4.1.js"></script>
			<script>  
				i = 0;  
				$(document).ready(function(){  
				    $("input").keypress(function(){  
						$("span").text (i += 1);  
				    });  
				});  
			</script> 
		</head>
		<body>
			Write something: <input type="text">  
			<p>Keypresses: <span>0</span></p>  
		</body>
	</html>

$("input").keypress(function(){ $("span").text (i += 1); it calculates how many times we press the key.