Question

我是一名初学程序员，他对此代码有困难，并希望得到任何反馈或帮助。此代码的目的是创建一个主要顾问，可以计算最适合放置哪所学校。我的编码问题是提交按钮没有连接而且case语句没有连接。请给我任何建议和任何反馈，你认为我可以做些什么来使这个正常工作。谢谢您的帮助。

<html>
<head>
<title>Major Adviser</title>
</head>
<body>
<script type=text/javascript>

function Calculate(a, b, c, d) {

var C = 0;
var SB = 0;
var S = 0;
var M = 0;
var SM = 0;
var LA = 0;
var GP = 0; 

function a(){
switch (document.ZF.elements.Hobbies)
  {
  case value=="Math":
    S + 2;
    SM + 3;
    LA + 1;
    break;
  case value=="Science":
    C + 2;
    SB + 2;
    M + 2;
    LA + 1;
    GP + 2;
    break;
  case value=="Computer Club":
SM + 1;
    C + 1;
    SB + 1;
    M + 2;
    LA + 2;
    GP + 1;
    break;
  case value=="Television Club":
    SM + 1;
    C + 1;
    SB + 1;
    M + 2;
    LA + 2;
    GP + 1;
    break;
  case value=="Community Service":
    SM + 1;
    C + 1;
    SB + 1;
    M + 2;
    LA + 2;
    GP + 1;
    break;
  case value=="Music":
    SM + 1;
    C + 1;
    SB + 1;
    M + 2;
    LA + 2;
    GP + 1;
    break;
case value=="Environmentalist":
    SM + 1;
    C + 1;
    SB + 1;
    M + 2;
    LA + 2;
    GP + 1;
break;
case value=="Acting":
    SM + 1;
    C + 1;
    SB + 1;
    M + 2;
    LA + 2;
    GP + 1;
break;
default:
    document.writeln("not working");
    }
}

function b(){

    switch (document.ZF.elements.Subject);
  {
  case value=="Math":
    S + 2;
    SM + 3;
    LA + 1;
    break;
  case value=="Science":
        C + 2;
        SB + 2;
       M + 2;
         LA + 1;
        GP + 2;
    break;
  case value=="Social Studies":
        SM + 1;
        C + 1;
        SB + 1;
        M + 2;
        LA + 2;
        GP + 1;
    break;
  case value=="English":
        SM + 1;
        C + 1;
        SB + 1;
        M + 2;
        LA + 2;
        GP + 1;
    break;
  case value=="Computers":
        SM + 1;
        C + 1;
        SB + 1;
        M + 2;
        LA + 2;
        GP + 1;
    break;
  case value=="Art":
        SM + 1;
        C + 1;
        SB + 1;
        M + 2;
        LA + 2;
        GP + 1;
    break;
default:
    document.writeln("not working");
    }
}

function c(){

switch (document.ZF.elements.type_of_person);
  {
  case value=="Introvert":
        S + 2;
        SM + 3;
        LA + 1;
    break;
  case value=="Extrovert":
        C + 2;
        SB + 2;
        M + 2;
        LA + 1;
        GP + 2;
    break;
  case value=="Both":
        SM + 1;
        C + 1;
        SB + 1;
        M + 2;
        LA + 2;
        GP + 1;
    break;
default:
    document.writeln("not working");
        }
}

function d(){

document.writeln("School of Communication and Arts: " + C);
document.writeln("School of Social and Behavioural Science: " + SB);
document.writeln("School of Science: " + S);
document.writeln("School of Science and Mathematics: " + SM);
document.writln("School of Management: " + M);
document.writln("School of Liberal Arts: " + LA);
document.writln("School of Global and Professional Programs: " + GP);

    }
    }
    </script>

<h1 align="right"><img src="Marist_College_2_220374.JPG" width="15%" height="15%" alt="Marist Logo"> <img src="poughkeepsie1.JPG" width="45%" height="15%" alt="Poughkeepsie"/> <img src="Marist_College_2_220374.JPG" width="15%" height="15%"       alt="Marist Logo"/>
</h1>

<h3 style="text-align:center">Marist Major Advisor</h3>
<form name="ZF">
First Name: <input type="text" name="firstname" size = 25 maxlength = 15> <br>
<br>
Last Name: <input type="text" name="lastname" size = 25 maxlength = 15> <br>
<br>
<p>What kind of Personality are you?</p>
<input type="radio" name="type_of_person" value="Introvert">Introvert<br>
<input type="radio" name="type_of_person" value="Extrovert">Extrovert<br>
<input type="radio" name="type_of_person" value="Both">Both<br>
<input type="radio" name="type_of_person" value="None">None<br>
<p>What are your best subjects/activities?</p>
<input type="checkbox" name="Subject" value="Math">Math<br>
<input type="checkbox" name="Subject" value="Science">Science<br>
<input type="checkbox" name="Subject" value="Social Studies">Social Studies<br>
<input type="checkbox" name="Subject" value="English">English<br>
<input type="checkbox" name="Subject" value="Computers">Computers<br>
<input type="checkbox" name="Subject" value="Art">Art<br>
<p>What activities or hobbies are you involved in?</p>
<input type="checkbox" name="Hobbies" value="Math">None<br>
<input type="checkbox" name="Hobbies" value="Science">Sports<br>
<input type="checkbox" name="Hobbies" value="Computer Club">Computer Club<br>
<input type="checkbox" name="Hobbies" value="Television Club">Television Club<br>
<input type="checkbox" name="Hobbies" value="Community Service">Community Service<br>
<input type="checkbox" name="Hobbies" value="Music">Music<br>
<input type="checkbox" name="Hobbies" value="Environmentalist">Environmentalist<br>
<input type="checkbox" name="Hobbies" value="Acting">Drama Class/Acting<br>
<p>How long are you willing to be in college for?</p>
<select>
    <option value="blank"></option>
    <option value="Don't Mind">Don't mind the amount of time.</option>
    <option value="2Year">2 years Associates Degree</option>
    <option value="4Year">4 years Bachelors Degree</option>
    <option value="4+">4+ Masters Degree</option>
    <option value="Doctrine">Doctrine</option>
</select><br>
<br>
<input type="button" value="Submit" onclick="Calculate()"/>
<input type="reset"Value="Clear">
</form>
</body>
</html>

Answer 1

由于您不熟悉编程，我需要指出几件事。

如果您打开任何现代浏览器并访问开发人员工具，则可能会遇到语法错误。例如，如果您在Firefox中，只需右键单击并选择Inspect Element with Firebug。这将让你自己开始。

所以这里有修复：

您需要<!DOCTYPE html>开头。
所有作业都需要从S + 2;更改为S += 2;。否则你需要做S = S +2;
如上所述，您可以从案例陈述中删除value ==。
如上所述，您有writln而不是writeln。
switch语句末尾有几个分号，不能存在。例如switch (document.ZF.elements.Subject);
对于“提交”按钮，我将type="button"更改为type="submit"，取代onclick代替jQuery .submit()事件。
switch语句没有使用value，它们只会查看第一个选中的语句。因此，需要for循环来提取checked值，并一次将它们传递给切换函数1。

我还清理了它的副本中的格式和语法结构，并添加了一些jQuery。

<!DOCTYPE html>
<html>
<head>
    <script src="http://code.jquery.com/jquery-1.9.1.js"></script>
    <meta charset="ISO-8859-1">
    <title>Major Adviser</title>
</head>
<body>
    <script type=text/javascript>
    $( document ).ready( function() {
        var C,SB,S,M,SM,LA,GP;

        $("#ZF").submit(function() {
            C = 0;
            SB = 0;
            S = 0;
            M = 0;
            SM = 0;
            LA = 0;
            GP = 0;

            var hobbies = $('.hobbies');
            for(var i = 0; i < hobbies.length; i++) {
              if (hobbies[i].checked) {
                var hobby;
                hobby = hobbies[i].value;
                a(hobby);
              }
            }

            var subjects = $('.subjects');
            for(var i = 0; i < subjects.length; i++) {
              if (subjects[i].checked) {
                var subject;
                subject = subjects[i].value;
                b(subject);
              }
            }

            c();
            d();
        });

        var a = function(hobby) {
            switch (hobby) {
            case "Math":
                S += 2;
                SM += 3;
                LA += 1;
                break;
            case "Science":
                C += 2;
                SB += 2;
                M += 2;
                LA += 1;
                GP += 2;
                break;
            case "Computer Club":
                SM += 1;
                C += 1;
                SB += 1;
                M += 2;
                LA += 2;
                GP += 1;
                break;
            case "Television Club":
                SM += 1;
                C += 1;
                SB += 1;
                M += 2;
                LA += 2;
                GP += 1;
                break;
            case "Community Service":
                SM += 1;
                C += 1;
                SB += 1;
                M += 2;
                LA += 2;
                GP += 1;
                break;
            case "Music":
                SM += 1;
                C += 1;
                SB += 1;
                M += 2;
                LA += 2;
                GP += 1;
                break;
            case "Environmentalist":
                SM += 1;
                C += 1;
                SB += 1;
                M += 2;
                LA += 2;
                GP += 1;
                break;
            case "Acting":
                SM += 1;
                C += 1;
                SB += 1;
                M += 2;
                LA += 2;
                GP += 1;
                break;
            default:
                document.writeln("not working");
            }
        };

        var b = function(subject) {
            switch (subject) {
            case "Math":
                S += 2;
                SM += 3;
                LA += 1;
                break;
            case "Science":
                C += 2;
                SB += 2;
                M += 2;
                LA += 1;
                GP += 2;
                break;
            case "Social Studies":
                SM += 1;
                C += 1;
                SB += 1;
                M += 2;
                LA += 2;
                GP += 1;
                break;
            case "English":
                SM += 1;
                C += 1;
                SB += 1;
                M += 2;
                LA += 2;
                GP += 1;
                break;
            case "Computers":
                SM += 1;
                C += 1;
                SB += 1;
                M += 2;
                LA += 2;
                GP += 1;
                break;
            case "Art":
                SM += 1;
                C += 1;
                SB += 1;
                M += 2;
                LA += 2;
                GP += 1;
                break;
            default:
                document.writeln("not working");
            }
        };

        var c=  function() {

            switch ($('.type_of_person').val()) {
            case "Introvert":
                S += 2;
                SM += 3;
                LA += 1;
                break;
            case "Extrovert":
                C += 2;
                SB += 2;
                M += 2;
                LA += 1;
                GP += 2;
                break;
            case "Both":
                SM += 1;
                C += 1;
                SB += 1;
                M += 2;
                LA += 2;
                GP += 1;
                break;
            default:
                document.writeln("not working");
            }
        };

        var d=  function() {

            document.writeln("School of Communication and Arts: " + C);
            document.writeln("School of Social and Behavioural Science: " + SB);
            document.writeln("School of Science: " + S);
            document.writeln("School of Science and Mathematics: " + SM);
            document.writeln("School of Management: " + M);
            document.writeln("School of Liberal Arts: " + LA);
            document.writeln("School of Global and Professional Programs: " + GP);

        };
    });
    </script>

    <h1 align="right">
        <img src="Marist_College_2_220374.JPG" width="15%" height="15%" alt="Marist Logo"> 
        <img src="poughkeepsie1.JPG" width="45%" height="15%" alt="Poughkeepsie" /> 
        <img src="Marist_College_2_220374.JPG" width="15%" height="15%" alt="Marist Logo" />
    </h1>

    <h3 style="text-align: center">Marist Major Advisor</h3>
    <form name="ZF" id="ZF">
        First Name: <input type="text" name="firstname" size=25 maxlength=15>
        <br> <br> 
        Last Name: <input type="text" name="lastname" size=25 maxlength=15> 
        <br> <br>
        <p>What kind of Personality are you?</p>
        <input type="radio" name="type_of_person" class="type_of_person" value="Introvert">Introvert<br>
        <input type="radio" name="type_of_person" class="type_of_person" value="Extrovert">Extrovert<br>
        <input type="radio" name="type_of_person" class="type_of_person" value="Both">Both<br>
        <input type="radio" name="type_of_person" class="type_of_person" value="None">None<br>
        <div id='subject-div'>
            <p>What are your best subjects/activities?</p>
            <input type="checkbox" name="Subject" class="subjects" value="Math">Math<br>
            <input type="checkbox" name="Subject" class="subjects" value="Science">Science<br>
            <input type="checkbox" name="Subject" class="subjects" value="Social Studies">Social Studies<br> 
            <input type="checkbox" name="Subject" class="subjects" value="English">English<br>
            <input type="checkbox" name="Subject" class="subjects" value="Computers">Computers<br>
            <input type="checkbox" name="Subject" class="subjects" value="Art">Art<br>
        </div>
        <div id='hobbies-div'>
            <p>What activities or hobbies are you involved in?</p>
            <input type="checkbox" name="Hobbies" class="hobbies" value="Math">Math<br>
            <input type="checkbox" name="Hobbies" class="hobbies" value="Science">Science<br>
            <input type="checkbox" name="Hobbies" class="hobbies" value="Computer Club">Computer Club<br> 
            <input type="checkbox" name="Hobbies" class="hobbies" value="Television Club">Television Club<br> 
            <input type="checkbox" name="Hobbies" class="hobbies" value="Community Service">Community Service<br> 
            <input type="checkbox" name="Hobbies" class="hobbies" value="Music">Music<br>
            <input type="checkbox" name="Hobbies" class="hobbies" value="Environmentalist">Environmentalist<br>
            <input type="checkbox" name="Hobbies" class="hobbies" value="Acting">Drama Class/Acting<br>
        </div>
        <p>How long are you willing to be in college for?</p>
        <select>
            <option value="blank"></option>
            <option value="Don't Mind">Don't mind the amount of time.</option>
            <option value="2Year">2 years Associates Degree</option>
            <option value="4Year">4 years Bachelors Degree</option>
            <option value="4+">4+ Masters Degree</option>
            <option value="Doctrine">Doctrine</option>
        </select><br> <br> 
        <input type="submit" value="Submit"/> 
        <input type="reset" Value="Clear">
    </form>
</body>
</html>

Answer 2

有许多不好的事情在继续：

您的案例陈述应为case "Math":
switch行末尾没有分号。
您的增量应为S += 2或SM += 3
您错误地拼写了writeln几次。
鉴于您如何使用C，SB等变量，它们应该是全球性的。
函数嵌套在Calculate中。删除所有这些内部功能。
您测试价值的方式不起作用。如果您使用的是现代浏览器，请尝试使用document.querySelector("[name=Subject]").value和其他类似的浏览器。
这在技术上并不重要，但你的变量名称是残暴的。我的意思是仁慈。

Answer 3

case value=="Computers":

应该是：

case "Computers":

等。您不需要value==部分。

此外，你有像这样的行中的拼写错误：

document.writln("School of Management: " + M); // writeln

Answer 4

Here's a working example to help you get started。请注意，版本有一些修改，可以使调试更容易。

以下是导致脚本崩溃的原因：

case语句不使用case value=="Math"之类的比较。以下是正确的格式

switch(n) {
  case 1:
    // execute code block
    break;
  case 2:
    // execute code block
    break;
  default:
    // code to execute if n is different from case 1 and 2
 }

除此之外，你还没有定义value！ value == 'Whatever'会引发ReferenceError

为了增加变量的值，您需要重新分配新值，如下所示：
```
var x = 0;
x + 1;     // `x` is still 1
x = x + 2; // `x` is now 2
x += 2;    // Shorthand for previous assignment; `x` is now 4
x++;       // Even shorter-hand for `x += 1`; `x` is now 5
```
因此S + 2;之类的语句不会更改S的值，您需要使用上面提到的其中一种形式（例如S += 2）来更改S的值Calculate
您似乎误解了应该如何使用参数（a.k.a.参数）。您的a函数实际上并不需要参数b，c，d或function a()以及您定义的后续方法（{{1}无法通过将值作为参数传递给Calculate来运行。只是为了澄清论证如何运作，这里是一个快速回顾。与数学函数非常相似，值被传递给JavaScript函数以在其中使用。考虑这个简单的multiply函数：
```
function multiply(x, y) {
  return x * y;
}
multiply(7, 3) // returns 21
```
这里我们发送了两个要在计算中使用的值。
如果您仍希望将每个switch语句保存在函数中，则需要稍后调用该函数。例如：
```
function greet(name) {
  function sayHello() {
    console.log('Hello ' + name + '!');
  }
  function askQuestion() {
    console.log('How are you ' + name + '?');
  }
  sayHello();
  askQuest();
}
```
虽然JavaScript确实允许在函数中嵌套函数，但只应明智地进行，例如when defining a class。这个例子不太合格。
document.ZF.elements.Whatever返回NodeList个对象，而不是checked元素的值。在提取值之前，您需要在列表中指定一个元素： var hobbies = document.ZF.elements.Hobbies; var hobby = hobbies [0] .value

如果您想累积多个复选框项目的分数，您需要迭代NodeList中的所有元素，同时通过分数计算功能。

var hobbies = document.ZF.elements.Hobbies;
for(var i = 0; i < hobbies.length; i++) {
  if (hobbies[i].checked) {
    var hobby;
    hobby = hobbies[i].value;
    calculateHobbyScore(hobby);
  }
}

您错误地将writeln拼错了writln几次！
您应该在浏览器中使用JavaScript控制台。它可以帮助您更轻松地捕获代码中的错误。您可以使用键盘快捷键CTRL + Shift + J
访问Chrome和Firefox中的JavaScript控制台
Chrome Console

Firefox Console

初学程序员在将JavaScript与案例陈述联系起来时遇到问题？

4 个答案: