<!DOCTYPE html>
<!--
switch来做计算器
-->
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
</head>
<body>
<input type="text" id="first" value="1">
<select>
<option value="1">+</option>
<option value="2">-</option>
<option value="3">*</option>
<option value="4">/</option>
<option value="5">%</option>
</select>
<input type="text" id="last" value="2">
<button id="btn">计算</button>
<p id="result"></p>
<script>
document.getElementById("btn").onclick = function () {
var first = document.getElementById("first");
var fValue = parseInt(first.value);
var last = document.getElementById("last");
var lValue = parseInt(last.value);
var select = document.getElementsByTagName("select")[0];
var add = select.value;
var n = parseInt(add);
var result = document.getElementById("result");
switch (n){
case 1:
result.innerHTML = fValue+ lValue;
break;
case 2:
result.innerHTML = fValue- lValue;
break;
case 3:
result.innerHTML = fValue* lValue;
break;
case 4:
result.innerHTML = fValue/ lValue;
break;
case 5:
result.innerHTML = fValue%lValue;
break;
}
}
</script>
</body>
</html>