<!DOCTYPE html>
<html>
<body>
<h1>JavaScript 运算符</h1>
<h2>** 运算符</h2>
<p>y = 5<br>计算 x = y ** 2：</p>
<p id="demo"></p>
<script>
let y = 5;
let x = y ** 2;
document.getElementById("demo").innerHTML = "x 的值是: " + x;
</script>
</body>
</html>