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求助求助

<!doctype html>

<html>

<head>

<title>無標題文檔</title>

function abc()

{

var tXt1=parseInt(document.getElementById('txt1').value);

var sel=documet.getElementById('select1').value;

var tXt2=parseInt(document.getElementById('txt2').value);

var result='';

switch(sel)

{

case '+':

result=tXt1+tXt2;

break;

case '-':

result=tXt1-tXt2;

break;

case '*':

result=tXt1*tXt2;

break;

case '/':

result=tXt1/tXt2;

break;

}

document.getElementById('txt3').value=result;

}

</script>

</head>

<body>

? ? <option value="-">-</option>

? ? <option value="*">*</option>

? ? <option value="/">/</option>

</select>

<input type="button" id="btn" ?value="=" onclick="abc()"/>?

</body>

</html>

慕瓜3177915

2016-08-14

源自：JavaScript進階篇 6-11

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3 回答

zssssssss 回答被采納 +3 積分
2016-08-14

sel定義那里document打錯了

?function?abc()
{
var?tXt1=parseInt(document.getElementById('txt1').value);
var?sel=document.getElementById('select1').value;
var?tXt2=parseInt(document.getElementById('txt2').value);
var?result='';
switch(sel)
{
case?'+':
result=tXt1+tXt2;
break;
case?'-':
result=tXt1-tXt2;
break;
case?'*':
result=tXt1*tXt2;
break;
case?'/':
result=tXt1/tXt2;
break;
}
document.getElementById('txt3').value=result;
}