我得到了無效的左手賦值錯誤和未定義的函數錯誤。任何人都可以幫助我?它基本上是一個計算器。Javascript/Html未捕獲ReferenceError:賦值時無效的左側;未捕獲ReferenceError:Calc未定義
//Calc.js: \t
var FirstNum = document.getElementById('FirstNum')
var SecondNum = document.getElementById('SecondNum')
var Method = document.getElementById('Method')
var Answer = document.getElementById('Answer')
\t
function Calc() {
if(Method.value == add) {
FirstNum.value + SecondNum.value = Answer.value
alert(Answer)
} else {
if(Method.value == subtract) {
FirstNum.value - SecondNum.value = Answer.value
alert(Answer)
} else if (Method.value == multiply){
FirstNum.value * SecondNum.value = Answer.value
alert(Answer)
} else if(Method.value == divide) {
Firstnum.value/SecondNum.value = Answer.value
alert(Answer)
} else {
alert("ERROR. You broke it :(")
}
}
}
<table border='1' align=center>
<tr align=center><td><b>First Number</b></td> <td><b>Second Number</b></td></tr>
<tr align=center>
<td align=center><input type="text" id="FirstNum" align=center></td>
<td align=center><input type="text" id="SecondNum" align=center></td>
</tr>
<tr>
<td><input type="radio" name="Method" value="add">+</td>
<td><input type="radio" name="Method" value="subtract">-</td>
</tr>
<tr>
<td><input type="radio" name="Method" value="multiply">*</td>
\t <td><input type="radio" name="Method" value="divide">/</td>
</tr>
<tr>
<td align=center><input type="button" value="=" onclick=Calc()></input></td>
<td align=center><input type="text" id="Answer" align=center></td>
</tr>
</table>
第一格式您的代碼 –
變量'subtract'應該來自哪裏?爲什麼你會期望DOM在加載之前做好準備?控制檯告訴你什麼? –
FirstNum.value + SecondNum.value = Answer.value? – lifetimes