level 3
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title></title>
</head>
<body>
<input type="number" onblur="n=value" value="" />
<select onchange="x=value">
<option value="+">+</option>
<option value="-">-</option>
<option value="*">*</option>
<option value="/">/</option>
</select>
<input type="number" onblur="m=value" value="" />
<input type="button" onclick="fnNum(this)" value="=" /><input type="number" value="" />
<script>
var n = '', x = '+', m = '';
function fnNum(e, v) {
if (n.trim() && m.trim()) {
switch (x) {
case '+':
v = Number(n) + Number(m);
break;
case '-':
v = n - m;
break;
case '*':
v = n * m;
break;
case '/':
v = n / m;
}
e.nextSibling.value = v;
}
}
</script>
</body>
</html>
2021年01月04日 04点01分
