Question

我正在为游戏创建一个计算器，我想使用下拉菜单在switch语句中选择一个值;虽然它似乎没有工作，它总是返回0.谁能看到我哪里出错了？另外我对java和html相当陌生，如果有一个愚蠢的错误，那就很抱歉。

这是我的HTML：

<form onsubmit="return calcDarkTroops(0);" style="display: inline;">
<!-- Title of Form /--> <font>Level</font> 
<!-- Gets Input /-->
<select id="minionlevel_input">
    <option>1</option>
    <option>2</option>
    <option>3</option>
    <option>4</option>
    <option>5</option>
    <option>6</option>
</select>
<!-- Calls 'calcDarkTroops' /-->
<input type="button" value="Calculate" onclick="calcDarkTroops();">
<!-- Outputs result /--> <span id="minioncost_result"> = 0 Dark Elixer</span>

这是我的Java：

calcDarkTroops = function () {
 var minionlevel = Number(document.getElementById("minionlevel_input").value);
 String maxString;
 switch (minionlevel) {
     case 1:
         maxString = "200,000";
         break;
     case 2:
         maxString = "190,000";
         break;
     case 3:
         maxString = "170,000";
         break;
     case 4:
         maxString = "140,000";
         break;
     case 5:
         maxString = "100,000";
         break;
     case 6:
         maxString = "0";

     document.getElementById("minioncost_result").innerHTML = "= " + Math.round(maxString * 100) / 100 + " Dark Elixer";

                        }

Answer 1

尝试为您的选择选项提供value属性，并考虑提供默认选项

<select id="minionlevel_input">
    <option value="0">Select</option>
    <option value="1">1</option>
    <option value="2">2</option>
    <option value="3">3</option>
    <option value="4">4</option>
    <option value="5">5</option>
    <option value="6">6</option>
</select>

FIDDLE

Answer 2

试试这个：

<form style="display: inline;">
<!-- Title of Form /--> <font>Level</font> 
<!-- Gets Input /-->
<select id="minionlevel_input">
    <option>1</option>
    <option>2</option>
    <option>3</option>
    <option>4</option>
    <option>5</option>
    <option>6</option>
</select>
<!-- Calls 'calcDarkTroops' /-->
<input type="button" value="Calculate" onclick="return calcDarkTroops(document.getElementById('minionlevel_input').value)">
<!-- Outputs result /--> <span id="minioncost_result"> = 0 Dark Elixer</span>

<script>
 function calcDarkTroops(minionlevel) {
   var maxString;
   switch (minionlevel) {
     case '1':
         maxString = "200,000";
         break;
     case '2':
         maxString = "190,000";
         break;
     case '3':
         maxString = "170,000";
         break;
     case '4':
         maxString = "140,000";
         break;
     case '5':
         maxString = "100,000";
         break;
     case '6':
         maxString = "0";
         break;    
   }
     document.getElementById("minioncost_result").innerHTML = "= " + Math.round(parseInt(maxString) * 100) / 100 + " Dark Elixer";

}

请参阅此fiddle

将<select>标签与Switch语句（Java和HTML）一起使用</select>

2 个答案: