老师检查作业
来源：4-14 项目作业
3颗猫饼干
2021-09-27 17:31:29
相关代码：
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>实现计算器的功能</title>
</head>
<body>
<input type='text' id='num1' />
<select id='operate'>
<option value='+'>+</option>
<option value="-">-</option>
<option value="*">*</option>
<option value="/">/</option>
</select>
<input type='text' id='num2' />
<input type='button' value=' = ' id="btn" />
<input type='text' id='result' />
<script>
// 得到表单元素
var num1 = document.getElementById('num1');
var operate = document.getElementById('operate');
var num2 = document.getElementById('num2');
var btn = document.getElementById('btn');
var result = document.getElementById('result');
var con ;
// 设置点击事件监听
btn.onclick = function () {
// 判断
if (operate.value == '+') {
con = Number(num1.value) + Number(num2.value);
}else if (operate.value == '-') {
con = Number(num1.value) - Number(num2.value);
}else if (operate.value == '*') {
con = Number(num1.value) * Number(num2.value);
}else if (operate.value == '/') {
con = Number(num1.value) / Number(num2.value);
}
result.value = con;
}
</script>
</body>
</html>写回答
1回答
-
好帮手慕慕子
2021-09-27
同学你好，代码效果实现是对的，继续加油，祝学习愉快~
0
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