I want to change onClick method in button in HTML with something other to not use onClick. I found on internet, addEventListener, but not sure how to replace here? Below are my code:
function leapYear() {
let input = document.getElementById("year");
let year = parseInt(input.value);
console.log(year);
let output = document.getElementById("output");
year = (year % 4 == 0) && (year % 100 != 0 || year % 400 == 0);
output.innerHTML = 'Year ' + year + '. is' + (year ? '' : ' not') + ' leap year.';
}<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
</head>
<body>
<h1>Leap Years</h1>
<p>Type a year:</p>
<div>
<input id="year" type="text" size="24" />
<button onclick="leapYear()">Check leap year</button> <br />
<span id="output"></span>
</div>
<script src="LeapYear.js"></script>
</body>
</html>Set the first parameter of addEventListener to 'click' and the second to the function:
function leapYear() {
let input = document.getElementById("year");
let year = parseInt(input.value);
console.log(year);
let output = document.getElementById("output");
year = (year % 4 == 0) && (year % 100 != 0 || year % 400 == 0);
output.innerHTML = 'Year ' + year + '. is' + (year && !isNaN(input.value) ? '' : ' not') + ' leap year.';
}
const button = document.querySelector('button');
button.addEventListener('click', leapYear)<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
</head>
<body>
<h1>Leap Years</h1>
<p>Type a year:</p>
<div>
<input id="year" type="text" size="24" />
<button>Check leap year</button> <br />
<span id="output"></span>
</div>
<script src="LeapYear.js"></script>
</body>
</html>