Question

在udemy上使用JavaScript进行在线课程。试着编写我学到的东西。我收到一个未定义的错误。 Visual Studio 2012 Pro说代码是找到的，但是当我运行代码时，我得到了错误。

        <script type="text/javascript">
        var numericalGrade = 82;
        var letterGrade;
        function myResaults() {
            document.write("Your score is " + numericalGrade + "%. Your grade will be a " + letterGrade + ".<br />");
        }

        if (numericalGrade >= 90) {
            letterGrade = "A";
            document.write(myResaults() + " Excellent, you passed this course with flying colors...");
        }

        else if (numericalGrade >= 80) {
            letterGrade = "B";
            document.write(myResaults() + " Excellent, you passed this course with a great grade..");

        }
        else if (numericalGrade >= 70) {
            letterGrade = "C";
            document.write(myResaults() + " Congratulations, you passed this course...");

        }
        else if (numericalGrade >= 60) {
            letterGrade = "D";
            document.write(myResaults() + " You revived a grade that will not permit you to pass this course. You can retake this course at a later date.");

        }
        else {
            letterGrade = "F";
            document.write(myResaults() + "You failed this course. You can retake this course at a later date.");

        }
    </script>

所以我做错了什么。我是JavaScript编码的新手。

Answer 1

你的函数需要返回一个值，但是因为它不是你得到的未定义。

变化：

function myResaults() {
    document.write("Your score is " + numericalGrade + "%. Your grade will be a " + letterGrade + ".<br />");
}

到

function myResaults() {
    return "Your score is " + numericalGrade + "%. Your grade will be a " + letterGrade + ".<br />";
}

VS中的JavaScript未定义错误

1 个答案: