现场演示：我的 HTML 文档

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>JavaScript try-catch-finally Statement</title>
</head>
<body>
    <script>
    // Assigning the value returned by the prompt dialog box to a variable
    var num = prompt("Enter a positive integer between 0 to 100");
    
    // Storing the time when execution start
    var start = Date.now();
    
    try {
        if(num > 0 && num <= 100) {
            alert(Math.pow(num, num)); // the base to the exponent power
        } else {
            throw new Error("An invalid value is entered!");
        }
    } catch(e) {
        alert(e.message);
    } finally {
        // Displaying the time taken to execute the code
        alert("Execution took: " + (Date.now() - start) + "ms");
    }
    </script>
    <p><strong>Note:</strong> The <code>Math.pow(base, exponent)</code> method returns a number representing the given base taken to the power of the given exponent i.e. <code>base<sup>exponent</sup></code>.</p>
</body>
</html>