尝试使用 html 中的下拉值创建一个函数，如下所示
<html>
<head>
<title>Taxi Fare</title>
<center><h1>Taxi Fare</h1>
<meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css">
<script>
function myAddition(){
var NorthAvenue = 0;
var QuezonAvenue = 4;
var GMAKamuning = 5;
var $sum = (40) + (place2 - place1) * (14);
window.alert("The sum is: " + $sum);
}
</script>
</head>
<body class="bg-warning">
<center>
<form method="post">
<select id="place1" name="place1">
<option value="NorthAvenue">North Avenue</option>
<option value="QuezonAvenue">Quezon Ave</option>
<option value="GMAKamuning">GMA Kamuning</option>
</select>
</form>
<form method="post">
<select id="place2" name="place2">
<option value="NorthAvenue">North Avenue</option>
<option value="QuezonAvenue">Quezon Ave</option>
<option value="GMAKamuning">GMA Kamuning</option>
</select>
<button type="button" onclick="myAddition(place2,place1)">Compute Fare</button>
</body>
</html>
但它总是返回“the sum is NaN”只是对这里的问题感到困惑
最佳答案
在你的脚本函数中放置两个像这样的参数 function myAddition(place2,place1)并将选择标签的值从文本更改为数字，如下所示
<select id="place1" name="place1">
<option value="0">North Avenue</option>
<option value="4">Quezon Ave</option>
<option value="5">GMA Kamuning</option>
</select>
<select id="place2" name="place2">
<option value="0">North Avenue</option>
<option value="4">Quezon Ave</option>
<option value="5">GMA Kamuning</option>
</select>
<button type="button" onclick="myAddition(document.getElementById('place2').value,document.getElementById('place1').value)">Compute Fare</button>
请以这种方式尝试您的代码
关于javascript - 如何使用下拉列表中的值在 javascript 中创建函数？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/60033516/