Question

尝试获取调用按钮，“check”以显示answer prompt1函数的var结果。无论出于什么原因，当我运行代码时，单击按钮时没有任何反应。我知道计算是正确的，因为当我设置答案按钮以提供预期警报时，它可以正常工作。如何获得第二个按钮以显示我输入的结果？

<!DOCTYPE html>

<head>

    <!--
        Name: Dakota Trumbull
        Date:
        Class:
        Purpose:
    -->
    <title>Math Test</title>





</head>

<body>

    <h1>Simple Math Test</h1>

    <p>Q1: 5 + 9 = ??</p>
        <button id = "Q1A" onclick = "answerPrompt1()">Answer</button>
        <button id = "Q1C" onclick ="showResult()">Check</button>

    <p></p>

    <p>Q2:  4 * 6 = ??</p>
        <button id = "Q2A">Answer</button>
        <button id = "Q2C">Check</button>

    <p></p>

    <p>Q3: 25 - 14 = ??</p>
        <button id = "Q3A">Answer</button>
        <button id = "Q3C">Check</button>

    <p></p>

    <p>Q4: 48 / 3 = ??</p>
        <button id = "Q4A">Answer</button>
        <button id = "Q4C">Check</button>

    <p></p>

    <p>Q5: 26 % 6 = ??</p>
        <button id = "Q5A">Answer</button>
        <button id = "Q5C">Check</button>

</body>

<script>



    //Q1


    function answerPrompt1()
    {
         var answer1 = prompt("Enter your answer: ");
         var convertedNum1 = parseInt(answer1, 10);
         var result = (convertedNum1 == 14)? "You're right!" :
            "Sorry, that's incorrect.";
    }
    function showResult()
    {
        alert(result);
    }

</script>

</html>

Answer 1

.as-console-wrapper { max-height: 100% !important; top: 0; }在result中声明，它赋予它本地范围（即在该函数之外不可见）。将声明移到函数前面：

＆＃13;

answerPrompt1

＆＃13;

var result = "You have not given an answer yet";
function answerPrompt1()
{
     var answer1 = prompt("Enter your answer: ");
     var convertedNum1 = parseInt(answer1, 10);
     result = (convertedNum1 == 14)? "You're right!" :
        "Sorry, that's incorrect.";
}
function showResult()
{
    alert(result);
}

＆＃13;

Answer 2

您应该以{{1}}和result两种功能都可以访问的方式更改answerPrompt1()变量。您可以清楚地了解javascript范围的工作原理{{3 }}

showResult()

警报消息按钮

2 个答案: