未捕获到的SyntaxError:计算时出现意外标识符 [英] Uncaught SyntaxError: Unexpected identifier at compute
问题描述
我有一些运行时返回 SyntaxError 的代码，但我不明白为什么.
I have some code that returns an Uncaught SyntaxError when I run it but I don't understand why.
我尝试将其通过JSHint进行，但无济于事.
I tried putting it through JSHint but to no avail.
以下代码显然是错误的:
Here is the code that is apparently wrong:
function compute(expr, x, string) {
var whatisx = "x=" + toString(x) + ",";
var tempAns = parseFloat(eval(whatisx + expr));
var roundedAnswer = roundNumber(tempAns, 3);
if (isNaN(tempAns) === true) {
alert("error");
}
if (string) {
return toString(roundedAnswer);
} else if (!string) {
return roundedAnswer;
} else {
return null;
console.log("Error trying to compute value. The string value must be boolean.");
}
}
运行它时，我没有任何控制台日志，并且说加号时出现错误:
When I run it, I don't get any console logs and it says there is an error at the plus sign in:
var tempAns = parseFloat(eval(whatisx + expr));
同一程序中的另一个问题也是SyntaxError，这是我的HTML.
Another problem in the same program that is also a SyntaxError is in my HTML.
这是我的html:
<!DOCTYPE html>
<html lang="en" dir="ltr">
<head>
<meta charset="utf-8">
<title>Grapher</title>
<script type="text/javascript" src="https://ajax.googleapis.com/ajax/libs/jquery/3.4.1/jquery.min.js" charset="utf-8"></script>
<script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/p5.js/0.8.0/p5.js" charset="utf-8"></script>
<script type="text/javascript" src="functions.js" charset="utf-8"></script>
<script type="text/javascript" src="sketch.js" charset="utf-8"></script>
</head>
<body>
<form>
<label>Graph y=</label>
<input id="mathExpr" type="text" name="mathExpr" value="">
<label> from x=</label>
<input id="x_min" type="text" name="x_min" value="">
<label> to </label>
<input id="x_max" type="text" name="x_max" value="">
<input type="button" name="result" value="Result" onclick="compute(); runp5();">
</form>
<h2>Answer: <span id="output"></span></h2>
</body>
</html>对于这个，它说在这里有一个错误
For this one, it says there is an error at
<input type="button" name="result" value="Result" onclick="compute(); runp5();">
该如何解决这两个问题?预先感谢.
What can I do to fix both of those? Thanks in advance.
编辑:问题已解决.我在没有任何参数的情况下调用了compute.(感谢@Pointy)
Question resolved. I was calling compute without any parameters. (thanks @Pointy)
推荐答案
我刚才回到了这个问题，我意识到自己犯了另一个错误.这是我的解决方法:
I came back to this question just now, and I realized I was making another mistake. Here is my fix:
-
正如Pointy用户所注意到的那样，我在调用
compute()时没有提供必需的参数.
As user Pointy noticed, I was calling
compute()without its required parameters.
我应该在 return 之前的 else 语句中添加 console.log()全部:
I should add console.log() in my else statement before the return otherwise it won't get called at all:
// ...
else {
console.log('message'); // this should come before return
return null;
}
这实际上并不能解决我详细说明的问题，但我想为以后的读者指出这一点.
This doesn't actually fix the problem I detailed, but I wanted to point it out for any future readers.
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