<!DOCTYPE?html>
<html>
?<head>
??<title>?事件</title>??
??<script?type="text/javascript">
???function?count(){
???????var?i=parselnt(document.getlementById("txt1").value);
???????var?j=parselnt(document.getlementById("txt2").value);
???????var?k=document.getlementById("select").value;
???????var?o;
???????switch(k){
???????????case?"+":
???????????????o=i+j;
???????????????break;
???????????case?"-":
???????????????o=i-j;
???????????????break;
???????????case?"*":
???????????????o=i*j;
???????????????break;
???????????case?"/":
???????????????o=i/j;
???????????????break;
???????}
???????document.getElementById("fruit").value=o;
????//獲取第一個輸入框的值
//獲取第二個輸入框的值
//獲取選擇框的值
//獲取通過下拉框來選擇的值來改變加減乘除的運算法則
????//設(shè)置結(jié)果輸入框的值?
????
???}
??</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>
2016-07-01
var i = parseInt(document.getElementById("txt1").value);
var j = parseInt(document.getElementById("txt2").value);
var k = document.getElementById("select").value;這三行的字母，你寫錯了，parseInt，，的I不對，Element的E你沒寫
2016-07-01
第7、8、9行的pareslnt應(yīng)該為paresInt 是Int不是lnt 大寫的 i ?還有后邊的getlementById少了個E getElementById 其他沒錯了