Question

我正在尝试制作一个简单的计算器，但我的函数calculate2（）并未被识别为函数。似乎变量FleetSize没有被正确定义为使用var的变量。或者我认为这可能是范围问题。但我无法弄清楚如何解决它。我试过并加倍检查了一切。请帮忙！这是代码：

<html>
<head>
    <title>Test</title>
</head>
<body>
    <form name="CNGSavingsCalculator">
        <table border="1" cellpadding="10" cellspacing="3">
            <tr>
                <th colspan="2">
                    <h1>CNG Savings Calculator</h1>
                </th>
            </tr>
            <tr>  
                <th>
                    <h3>INPUT</h3>
                </th>
                <th>
                    <h3>OUTPUT</h3>
                </th>    
            </tr>
            <tr> 
                <td>
                    Fleet Size: <input type="number" value="10" name="FleetSize" id="FleetSize" onchange="calculate2();"/> trucks<br>
                    Average  Miles Per Year: <input type="number" value="50000" name="Miles" id="Miles" onchange="calculate2();"> miles<br>
                    Average Diesel MPG: <input type="number" value="6" name="MPG" id="MPG" onchange="calculate2();"> MPG<br>
                    Diesel Cost: $<input type="number" value="4.5" name="DieselCost" id="DieselCost" onchange="calculate2();"><br>
                    Natural Gas Cost: $<input type="number" value="1.75" name="NaturalGasCost" id="NaturalGasCost" onchange="calculate2();"><br>
                    Incremental NG Truck Cost: $<input type="number" value="50000" name=IncrementalCost" id="IncrementalCost" onchange="calculate2();"><br>
                    Government Incentives: $<input type="number" value="32000" name="GovernmentIncentives" id="GovernmentIncentives" onchange="calculate2();"><br>
                </td>
                <td>
                    <table border="1" cellpadding="10" cellspacing="3">
                        <tr>
                            <th>Natural Gas</th>
                            <th>Diesel</th>
                        </tr>
                        <tr>
                            <td><input type="number" value="99224" name="GallonsNaturalGasUsed" id="GallonsNaturalGasUsed"><br>Gallons Equivalent Used</td>
                            <td><input type="number" value="83333" name="GallonsDieselUsed" id="GallonsDieselUsed"><br>Gallons Diesel Used</td>
                        </tr>
                        <tr>
                            <td>$<input type="number" value="183102" name="TotalAnnualNaturalGasCost" id="TotalAnnualNaturalGasCost"><br>Total Annual Fuel Cost</td>
                            <td>$<input type="number" value="375000" name="TotalAnnualDieselCost" id="TotalAnnualDieselCost"><br>Total Annual Fuel Cost</td>
                        </tr> 
                    </table><br>
                    <table border="1" cellpadding="10" cellspacing="3">
                        <tr>
                            <th>Results</th>
                        </tr>
                        <tr>
                            <td>Payback on Incremental<br>Truck Cost: <input type="number" value="0.94" name="ROI" id="ROI"> Years</td>
                        </tr>
                        <tr>
                            <td>Annual Fuel Savings<br>$<input type="number" value="191898" name="AnnualFuelSavings" id="AnnualFuelSavings"></td>
                        </tr>
                    </table>
                </td>
            </tr>
        </table>
    </form>
</body>
<script type="text/javascript">
    function calculate2() {
        var FleetSize = document.CNGSavingsCalculator.FleetSize.value,
        var Miles = document.CNGSavingsCalculator.Miles.value,
        var MPG = document.CNGSavingsCalculator.MPG.value,
        var DieselCost = document.CNGSavingsCalculator.DieselCost.value,
        var NaturalGasCost = document.CNGSavingsCalculator.NaturalGasCost.value,
        var IncrementalCost = document.CNGSavingsCalculator.IncrementalCost.value,
        var GovernmentIncentives = document.CNGSavingsCalculator.GovernmentIncentives.value,
            GallonsNaturalGasUsed = 10*FleetSize;
            GallonsDieselUsed = 20*Miles;
        document.CNGSavingsCalculator.GallonsNaturalGasUsed.value = GallonsNaturalGasUsed;
        document.CNGSavingsCalculator.GallonsDieselUsed.value = GallonsDieselUsed
    }
</script>
</html>

非常感谢！

Answer 1

您可以在语句开头使用var来声明其中的所有变量。

您可以使用逗号在var之后列出多个变量。

您将var放在,之后（很多次），这是一个错误。

要么摆脱var（除了第一个）或用半冒号取代,来终止声明。

JSHint是一个有用的调试工具。它报道：

3意外'var'。3预期标识符，而不是'var'（a 保留字）。
3缺少分号。

Answer 2

您使用的语法错误。我的代码片段显示了如何声明变量：

//Either this way:
var a = "something",
    b = 1,
    c = "another";

//Or this way:
var a = "something";
var b = 1;
var c = "antoher";

提及“，”和“;”你一直在做错。据我所知，你正在反过来使用它; P

您的代码已清理完毕：

function calculate2() {
    var FleetSize = document.CNGSavingsCalculator.FleetSize.value,
        Miles = document.CNGSavingsCalculator.Miles.value,
        MPG = document.CNGSavingsCalculator.MPG.value,
        DieselCost = document.CNGSavingsCalculator.DieselCost.value,
        NaturalGasCost = document.CNGSavingsCalculator.NaturalGasCost.value,
        IncrementalCost = document.CNGSavingsCalculator.IncrementalCost.value,
        GovernmentIncentives = document.CNGSavingsCalculator.GovernmentIncentives.value,
        GallonsNaturalGasUsed = 10*FleetSize,
       GallonsDieselUsed = 20*Miles;
    document.CNGSavingsCalculator.GallonsNaturalGasUsed.value = GallonsNaturalGasUsed;
    document.CNGSavingsCalculator.GallonsDieselUsed.value = GallonsDieselUsed;
}

我的函数没有被识别为函数，var没有定义我的变量

2 个答案: