Question

我正在制作基本的usd转换器，用于练习html / javascript。但是，当我选择欧元选项时，它与peso选项的作用相同。

<html>
    <head>
        <title>Currency Converter</title>
        <style>

        </style>
    </head>
    <body>
        <input id="amount"> </input>
        <p>usd Contverted to</p> 
        <p class="output"> </p>
        <select id="select"> <option value="1">Peso's</option> <option value="2">Euro's</option> </select>
        <p id="answer"> is </p>
        <input type="submit" value="Submit" onclick="run()"> 
        <script>
            function run() {
                var Amount = document.getElementById("amount").value;
                if (select = 1) {
                    document.getElementById("answer").innerHTML = "=-=-= " + Amount * 16.39  + "   =-=-=";
                } else if (select = 2) {
                    document.getElementById("answer").innerHTML = "=-=-= " + Amount * 0.9  + "   =-=-=";
                } else {
            }
        </script>
    </body>
</html>

Answer 1

您没有比较选择，您正在设置它。

   if (select == 1) {
       document.getElementById("answer").innerHTML = ...
   } else if (select == 2) {

= - ＆gt;设置值
== - ＆gt;比较

Answer 2

它应该是select == 1 select=1将始终返回true，因为这样您只需分配值，而不是检查相等性

Answer 3

您没有获得选择
您没有比较如果条件中的选择值，请将其设为 select == 1 并选择== 2 < /强>

<强> Complete solution here

更改您的javaScript函数，如下所示

function run() { var Amount=document.getElementById("amount").value; var select=document.getElementById("select").value; if (select == 1) { document.getElementById("answer").innerHTML = "=-=-= " + Amount * 16.39 + " =-=-="; } else if (select == 2) { document.getElementById("answer").innerHTML = "=-=-= " + Amount * 0.9 + " =-=-="; } else { } }

麻烦用html输入框

3 个答案: