我很难把美元兑换成欧元。我把欧元兑换成美元,没有太大的麻烦,但我有更多的困难,把美元兑换成欧元。以下是我的代码:(我还添加了我的HTML代码)
function init() {
// change color of input field
$("#euro").css("background-color", "lightgreen");
$("#dollar").css("background-color", "lightgreen");
// perform conversion when button is clicked
$("#convert1").click(function() {
// get value from euro input
var amountStr = $("#euro").val();
if (amountStr == "") {
// no value has been entered
alert("Please enter a value!");
}
else {
// convert amountStr to float
var amount = parseFloat(amountStr);
// check if amount is NaN (happens when string is entered into input field)
if (isNaN(amount)) {
alert("Invalid input!");
}
else {
// do the conversion
var dollar = euroToDollar(amount);
// put dollar value in dollar field
$("#dollar").val(dollar);
<html>
<head>
<meta charset="utf-8">
<title>Currency Converter</title>
<link rel="stylesheet" href="index.css">
<script src="jquery-1.11.0.min.js"></script>
<script src="index.js"></script>
</head>
<body onload="init()">
Euro: <input type="text" id="euro" name="euro"/>
Dollar: <input type="text" id="dollar" name="dollar"/>
<button id="convert1">Convert</button>
<button id="convert2">Enhanced convert</button>
</body>
</html>
这应该可以工作:
function init() {
// change color of input fields
$("#euro").css("background-color", "lightgreen");
$("#dollar").css("background-color", "lightgreen");
// perform conversion when button is clicked
$("#convert1").click(function() {
// get value from inputs
var dollarStr = $("#dollar").val();
var euroStr = $("#euro").val();
if (dollarStr == "" && euroStr == "") {
// no value has been entered
alert("Please enter a value!");
}
else if (dollarStr == "") {
// convert euroStr to float
var amount = parseFloat(euroStr);
// check if amount is NaN (happens when string is entered into input field)
if (isNaN(amount)) {
alert("Invalid input!");
}
else {
// do the conversion
var dollar = euroToDollar(amount);
// put dollar value in dollar field
$("#dollar").val(dollar);
}
}
else if (euroStr == "") {
// convert dollarStr to float
var amount = parseFloat(dollarStr);
// check if amount is NaN (happens when string is entered into input field)
if (isNaN(amount)) {
alert("Invalid input!");
}
else {
// do the conversion
var euro = dollarToEuro(amount);
// put dollar value in dollar field
$("#euro").val(euro);
}
}
else {
// value has been entered in both input boxes
alert("Please only enter a value into one of the boxes.");
}
});
}