我收到无效的左手赋值错误和未定义的函数错误。有人能帮助我吗?它基本上是一个计算器。
//Calc.js:
var FirstNum = document.getElementById('FirstNum')
var SecondNum = document.getElementById('SecondNum')
var Method = document.getElementById('Method')
var Answer = document.getElementById('Answer')
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>
<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>
试试这个。你的错误基本上是分配方向:
<!DOCTYPE html>
<html>
<head>
<title></title>
<meta name="viewport" content="width=device-width, initial-scale=1">
</head>
<body>
<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>
<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>
<script>
//Calc.js:
var FirstNum = document.getElementById('FirstNum')
var SecondNum = document.getElementById('SecondNum')
var Method = document.getElementsByName('Method')
var Answer = document.getElementById('Answer')
function getRadioValue(theRadioGroup)
{
var elements = document.getElementsByName(theRadioGroup);
for (var i = 0, l = elements.length; i < l; i++)
{
if (elements[i].checked)
{
return elements[i].value;
}
}
}
function Calc(){
if(getRadioValue("Method") == "add"){
Answer.value = parseFloat(FirstNum.value) + parseFloat(SecondNum.value) ;
} else{
if(getRadioValue("Method") == "subtract"){
Answer.value = parseFloat(FirstNum.value) - parseFloat(SecondNum.value);
}else
if(getRadioValue("Method") == "multiply"){
Answer.value = parseFloat(FirstNum.value) * parseFloat(SecondNum.value) ;
} else
if(getRadioValue("Method") == "divide"){
Answer.value = parseFloat(FirstNum.value) / parseFloat(SecondNum.value) ;
}
else{
alert("ERROR. You broke it :(")
}
}
}
</script>
</body>
</html>