<!DOCTYPE html><html>?<head>? <title> 事件</title> ?? <script type="text/javascript">?? function count(){?????? var a=document.getElementById("txt1").value;??? //獲取第一個輸入框的值?????? var b=document.getElementById("txt2").value;?? ?//獲取第二個輸入框的值?????? var c=document.getElementById("select").value;?????? var z;?? ?//獲取選擇框的值??? switch(c)??? {??????? case "+":??????????? z=a+b;??????????? break;??????? case "-":??????????? z=a-b;??????????? break;?? ???????? case "*":??????????? z=a*b;??????????? break;??????? default:??????????? z=a/b;????????????? ???? }?? ?//獲過下拉框來選擇的值來改變加減乘除的運算法則??? //設置結果輸入框的值??? document.getElementById("fruit").value=z;?? ??? }? </script> ?</head> ?<body>?? <input type='text' id='txt1' /> ?? <select id='select'>?? ??? ?<option value='+'>+</option>?? ??? ?<option value="-">-</option>?? ??? ?<option value="*">*</option>?? ??? ?<option value="/">/</option>?? </select>?? <input type='text' id='txt2' /> ?? <input type='button' value=' = ' onclick="count()"/> <!--通過 = 按鈕來調用創建的函數，得到結果--> ?? <input type='text' id='fruit' />? ??</body></html>
1+2怎么是12，減乘除都還對。。？計算器程序
Timewatcher
2016-06-02 13:50:24
