Leslie继续宠爱
2015-01-24 21:41
<!DOCTYPE html>
<html>
<head>
<title> 事件</title>
<script type="text/javascript">
function count(){
var m=document.getElementById("txt1").value;
var b=document.getElementById("txt2").value;
var c =document.getElementById("select").value;
//获取通过下拉框来选择的值来改变加减乘除的运算法则
var result="";
switch(c){
case '+':
result=parseInt(m)+parseInt(b) ;
break;
case '-':
result=parseInt(m)-parseInt(b);
break;
case '*':
result=parseInt(m)*parseInt(b) ;
break;
default '/':
result=parseInt(m)/parseInt(b) ;
break;
}
document.getElementById("fruit")=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()";/> <!--通过 = 按钮来调用创建的函数,得到结果-->
<input type='text' id='fruit' />
</body>
</html>
简单来说 document.getElementById("fruit")=result;少个.value
default '/':
result=parseInt(m)/parseInt(b) ;
break;
default应该改成case
<!DOCTYPE html>
<html>
<head>
<title> 事件</title>
<script type="text/javascript">
function count(){
var m=document.getElementById("txt1").value;
var b=document.getElementById("txt2").value;
var c =document.getElementById("select").value;
//获取通过下拉框来选择的值来改变加减乘除的运算法则
var result="0";
switch(c){
case '+':
alert("+++");
result=parseInt(m)+parseInt(b) ;
break;
case '-':
result=parseInt(m)-parseInt(b);
break;
case '*':
result=parseInt(m)*parseInt(b) ;
break;
case '/':
result=parseInt(m)/parseInt(b) ;
break;
}
alert(result);
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();"/>
<input type='text' id='fruit' />
</body>
</html>JavaScript进阶篇
469182 学习 · 22584 问题
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