开始Javascript第2章,完成练习2



我正在学习初级Javascript,但无法通过第二章完成练习2。练习是纠正这段代码

 <!DOCTYPE html>
<html lang="en">
<head>
    <title>Chapter 2, Finishing exercise 2</title>
</head>
<body>
    <script>
        var firstNumber = prompt("Enter the first number", "");
        var secondNumber = prompt("Enter the second number", "");
        var theTotal = firstNumber + secondNumber;
        document.write(firstNumber + " added to " + secondNumber + " equals " theTotal);
    </script>
</body>
</html>

我可以使用alert获得正确的总数,但是当我删除注释时,它不再工作。

<!DOCTYPE html>
<html lang="en">
<head>
    <title>Chapter 2, Finishing exercise 2</title>
</head>
<body>
    <script>
        var firstNumber = prompt("Enter the first number", "");
        var secondNumber = prompt("Enter the second number", "");

        var intFirstNumber = parseInt(firstNumber, 10);
        var intSecondNumber = parseInt(secondNumber, 10);
        var theTotal = intFirstNumber + intSecondNumber;

        alert(theTotal);
        //document.write (intFirstNumber + " added to " + intSecondNumber + " equals " theTotal);
    </script>
</body>
</html>

我不知道我的文件怎么办。写的陈述是错误的。有提示吗?此外,是否有更优雅的方式来实现我正在做的事情?

"equals"theTotal之间需要另一个+:

document.write(firstNumber + " added to " + secondNumber + " equals " + theTotal);

在此上下文中,+符号表示将它后面的内容连接(追加)到它前面的内容。


进一步阅读:

字符串连接的MDN文档。

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