Question

我在努力让美元兑换成欧元时遇到了麻烦。我有欧元转换成美元并没有太大的麻烦，但我有更多的困难，让美元兑换成欧元。这是我的代码:(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>

Answer 1

这应该有用：

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.");
        }
    });
}

麻烦美元到欧元

1 个答案: