我这辈子都头疼了。我不太擅长 Javascript，所以我不知道发生了什么。我应该编写一个文本框，当输入价格并提交时，它将计算运费并告诉您总数。除了未设置键入的值之外，一切正常。因此，无论输入什么，价格似乎都永久设置为 NaN。我究竟做错了什么？ D:
<!DOCTYPE html>
<html>
<head>
<title>Untitled Document</title>
</head>
<body>
<form method="post" name="number" onsubmit='window.alert("Your total is $" + total + ".");'>
<input type="text" name="purchasePrice" placeholder="0.00" />
<input type="submit" value="submit" />
</form>
<script>
/* <![CDATA[ */
var price = parseFloat(document.getElementsByTagName("input")[0].value);
var shipping = parseFloat(calculateShipping(price));
var total = price + shipping;
function calculateShipping(price) {
if (price <= 25) {
return 1.5;
} else {
return price * 10 / 100
}
}
/* ]]> */
</script>
</body>
</html>
最佳答案
这是一个可能对您有帮助的示例
<input id="amount" type="text" name="purchasePrice" placeholder="0.00" />
<input id="submit" type="submit" value="submit" />
var amount = document.getElementById("amount");
var submit = document.getElementById("submit");
function calculateShipping() {
var price = parseFloat(amount.value) || 0;
if (price <= 25) {
alert("Your total is $" + 1.5);
} else {
alert("Your total is $" + (price * 10 / 100));
}
}
submit.addEventListener("click", calculateShipping, false);
关于 jsfiddle
关于Javascript 运费计算器不抓取输入，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/16133690/