折 騰
搞了半天。
鈺茹她爹
2015-08-18
1 回答
舉報
0/150
提交
取消
2015-08-18
舉報
2015-12-15
<!DOCTYPE html>
<html>
?<head>
? <title> 事件</title> ?
? <script type="text/javascript">
?? function count(){
????? ?
??? //獲取第一個輸入框的值
??? var txt1Val = document.getElementById("txt1").value;
? //獲取第二個輸入框的值
??? var txt2Val = document.getElementById("txt2").value;
? //獲取選擇框的值
??? var opera =? document.getElementById("select");
??? var index =? opera.selectedIndex;
??? var operaVal = opera.options[index].value;
??? var result;
? //獲取通過下拉框來選擇的值來改變加減乘除的運算法則
? if(operaVal == "+"){ ?
?? result = (txt1Val-0) + (txt2Val-0);
? }else if(operaVal == "-"){
?? result = txt1Val - txt2Val;
? }else if(operaVal == "*"){?? ?
?? result = txt1Val * txt2Val;
? }else{? ?
?? result = txt1Val / txt2Val;
? }
?? console.log(txt1Val+"`````````"+txt2Val+"`````````"+result)
??? //設(shè)置結(jié)果輸入框的值
??? document.getElementById("fruit").value = result
?? }
? </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(diào)用創(chuàng)建的函數(shù)，得到結(jié)果-->
?? <input type='text' id='fruit' />? ?
?</body>
</html>