Question

我正在尝试制作一个javascript程序，当你给它输入时解决了毕达哥拉斯定理。但由于某种原因，它不起作用。这是代码：`

<!DOCTYPE html>
<html>
<head>
    <link rel='stylesheet' href='style.css'/>
    <script>
       var a = document.getElementById("a").value;
       var b = document.getElementById("b").value; 
        function myFunction() {
    var one = Math.pow(a, 2);
    var two = Math.pow(b, 2);
    var xone = (one+two);
    var c = Math.sqrt(xone);
    alert("c="+c);

}
    </script>
</head>
<body>

<strong>A</strong>
<input type="text" id="a"></input> <br>
<strong>B</strong>
<input type="text" id="b"></input><br>
<button onclick="myFunction()">Enter</button>
</body>
</html>

Answer 1

首先，您需要移动函数内部的数据收集。否则你将永远不会有输入值。

<!DOCTYPE html>
<html>
<head>
    <link rel='stylesheet' href='style.css'/>
    <script>
        function myFunction() {
       //moved two lines below so they are inside the function declaration.
       var a = document.getElementById("a").value;
       var b = document.getElementById("b").value; 
    var one = Math.pow(a, 2);
    var two = Math.pow(b, 2);
    var xone = (one+two);
    var c = Math.sqrt(xone);
    alert("c="+c);

}
    </script>
</head>
<body>

<strong>A</strong>
<input type="text" id="a"></input> <br>
<strong>B</strong>
<input type="text" id="b"></input><br>
<button onclick="myFunction()">Enter</button>
</body>
</html>

Answer 2

只需将脚本部分替换为以下部分：

<script>
        function myFunction() {
    var a = document.getElementById("a").value;
    var b = document.getElementById("b").value;
    var one = Math.pow(a, 2);
    var two = Math.pow(b, 2);
    var xone = (one+two);
    var c = Math.sqrt(xone);
    alert("c="+c);

}
    </script>

您所要做的就是移动getElementById行以确认函数：）

这个JavaScript代码我做错了什么？

2 个答案: