<!DOCTYPE html>
<html>
<body>
<h2>JavaScript if .. else</h2>
<p>時間に応じた挨拶:</p>
<p id="demo"></p>
<script>
const hour = new Date().getHours();
let greeting;
if (hour < 18) {
greeting = "こんにちは";
} else {
greeting = "こんばんは";
}
document.getElementById("demo").innerHTML = greeting;
</script>
</body>
</html>
