mxdi9i7/index.html

## index.html
<!Doctype html>
	<html>
		<head>
			<meta charset="UTF-8">
		</head>
		<body>
			<input type="number" id="input1">
			<button id="btn">Calculate</button>
			<h1 id="demo"></h1>
		</body>
		<script src="index.js"></script>
	</html>

## index.js
var input1 = document.getElementById('input1')
var btn = document.getElementById('btn')
var demo = document.getElementById('demo');

function evenOrOdd(x) {
	if (x == 0) {
		demo.innerHTML = "0 既不是奇数也不是偶数"
	} else if (x % 2 == 0) {
		demo.innerHTML = x + " 是偶数"
	} else {
		demo.innerHTML = x + ' is Odd'
	}
}

for(var i = 0; i < 5; i++) {
	console.log('这次循环, i 是 ' + i)
}

btn.addEventListener('click', function() {
	evenOrOdd(input1.value)
})
	<!Doctype html>
	<html>
	<head>
	<meta charset="UTF-8">
	</head>
	<body>
	<input type="number" id="input1">
	<button id="btn">Calculate</button>
	<h1 id="demo"></h1>
	</body>
	<script src="index.js"></script>
	</html>
	var input1 = document.getElementById('input1')
	var btn = document.getElementById('btn')
	var demo = document.getElementById('demo');

	function evenOrOdd(x) {
	if (x == 0) {
	demo.innerHTML = "0 既不是奇数也不是偶数"
	} else if (x % 2 == 0) {
	demo.innerHTML = x + " 是偶数"
	} else {
	demo.innerHTML = x + ' is Odd'
	}
	}

	for(var i = 0; i < 5; i++) {
	console.log('这次循环, i 是 ' + i)
	}

	btn.addEventListener('click', function() {
	evenOrOdd(input1.value)
	})