加减乘除运算 为什么没有结果显示
<!DOCTYPE html>
<html>
<head>
<title> 事件</title>
<script type="text/javascript">
function count(){
var Txt1=document.getElementById("txt1");
var Txt2=document.getElementById("txt2");
var Select=document.getElementById("select");
var result;
switch(Select)
{ case "+":
result=parseInt(Txt1.value)+parseInt(Txt2.value);
break;
case "-";
result=parseInt(Txt1.value)-parseInt(Txt2.value);
break;
case "*":
result=parseInt(Txt1.value)*parseInt(Txt2.value);
break;
default:
result=parseInt(Txt1.value)/parseInt(Txt2.value);
break;
}
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()" /> <!--通过 = 按钮来调用创建的函数，得到结果-->
<input type='text' id='fruit' />
</body>
</html>
qq_天空下起了鱼_03回答
-
李晓健
function count(){ var Txt1=document.getElementById("txt1"); var Txt2=document.getElementById("txt2"); var Select=document.getElementById("select"); var result; //这里要取值 switch(Select.value) { case "+": result=parseInt(Txt1.value)+parseInt(Txt2.value); break; //这里是 : 不是 ; case "-": result=parseInt(Txt1.value)-parseInt(Txt2.value); break; case "*": result=parseInt(Txt1.value)*parseInt(Txt2.value); break; default: result=parseInt(Txt1.value)/parseInt(Txt2.value); break; } document.getElementById("fruit").value=result; }看注释 -
李晓健
function count(){ var Txt1=document.getElementById("txt1"); var Txt2=document.getElementById("txt2"); var Select=document.getElementById("select"); var result; //这里要取值 switch(Select.value) { case "+": result=parseInt(Txt1.value)+parseInt(Txt2.value); break; //这里是 : 不是 ; case "-": result=parseInt(Txt1.value)-parseInt(Txt2.value); break; case "*": result=parseInt(Txt1.value)*parseInt(Txt2.value); break; default: result=parseInt(Txt1.value)/parseInt(Txt2.value); break; } document.getElementById("fruit").value=result; }看注释
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相关分类
JavaScript