4-14，麻烦老师检查一下！
来源：4-14 项目作业
脑袋瓜瓜嗡嗡的
2022-06-13 17:08:58
<!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>Document</title>
<script>
window.onload = function(){
var oOption = document.getElementsByTagName("option");
// var oOperate = document.getElementsById("operate");
var oNum1 = document.getElementById("num1");
var oNum2 = document.getElementById("num2");
var oResult = document.getElementById("result");
var oBtn = document.getElementById("btn");
oBtn.onclick = function(){
for(var i = 0;i < oOption.length;i++){
if(oOption[i].selected == true){
switch (oOption[i].value){
case "+":
oResult.value = Number(oNum1.value)+Number(oNum2.value);
break;
case "-":
oResult.value = Number(oNum1.value)-Number(oNum2.value);
break;
case "*":
oResult.value = Number(oNum1.value)*Number(oNum2.value);
break;
case "/":
oResult.value = Number(oNum1.value)/Number(oNum2.value);
break;
}
console.log(oNum1.value);
console.log(oNum2.value);
console.log(oResult.value);
break;
}
}
}
}
</script>
</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'>
</body>
</html>写回答
1回答
-
同学你好，代码效果正确，注释代码中获取id元素单词拼写错误，直接省去for循环以及if判断，给个变量，把获取的value属性值赋给它；var num = operate.value;参考如下图：
祝学习愉快~
0
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