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<!DOCTYPE html>

<html>

?<head>

? <title> 事件</title> ?

? <script type="text/javascript">

? ?function count(){

? ? ? ?

? ? //獲取第一個(gè)輸入框的值

? ? var a=document.getElementById("txt1").value;

//獲取第二個(gè)輸入框的值

? ? var b=document.getElementById("txt2").value;

//獲取選擇框的值

? ? document.getElementById("select").value;

//獲取通過下拉框來選擇的值來改變加減乘除的運(yùn)算法則

? ? switch(select.value){

? ? ? ? case'+':total=a*1+b*1;break;

? ? ? ? case'-':total=a-b;break;

? ? ? ? case'*':total=a*b;break;

? ? ? ? case'/':total=a/b;break;

? ? }

? ? //設(shè)置結(jié)果輸入框的值?

? ? ?document.getElementById("fruit").value=total;

? ?}

? </script>?

?</head>?

?<body>

?

? ?<input type="text" id="txt1" />?

? ?<select id="select">

? ?</select>

? ?<input type="text" id="txt2" />?

? ?<input type="button" value="= " /> ?

? ?<input type="text" id="fruit" name=total onClick="count('select')" /> ??

??

?</body>

</html>

Vincent_Eson

2015-04-15

源自：JavaScript進(jìn)階篇 6-11

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1 回答

王家逸
2015-12-14

<!DOCTYPE?html>
<html>
?<head>
??<title>?事件</title>??
??<script?type="text/javascript">
???function?count(){
????var?txt1?=?document.getElementById("txt1").value;
????//獲取第一個(gè)輸入框的值
????var?txt2?=?document.getElementById("txt2").value;
	//獲取第二個(gè)輸入框的值
????var?select?=?document.getElementById("select").value;
	//獲取選擇框的值
????var?result?=?"";
????switch(select){
????????case?'+':
????????????result?=?parseInt(txt1)?+?parseInt(txt2);
????????????break;
????????case?'-':
????????????result?=?parseInt(txt1)?-?parseInt(txt2);
????????????break;
????????case?'*':
????????????result?=?parseInt(txt1)?*?parseInt(txt2);
????????????break;
????????default:
????????????result?=?parseInt(txt1)?/?parseInt(txt2);
????????????break;
????}
	//獲取通過下拉框來選擇的值來改變加減乘除的運(yùn)算法則
????document.getElementById("fruit").value?=?result;
????//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>