代码示例:(标识:eg_js_datatypes_number_large)
<!DOCTYPE html>
<html>
<body>

<h2>JavaScript 数值</h2>

<p>超大或超小的数值可以用科学计数法来写:</p>

<p id="demo"></p>

<script>
var y = 123e5;
var z = 123e-5;

document.getElementById("demo").innerHTML =
y + "<br>" + z;
</script>

</body>
</html>
运行结果: