如何修复此语法错误？

发布于 2024-07-28 22:06:21 字数 495 浏览 4 评论 0原文

代码是：

  function roundAmount(theDecimal) { 
    var s = "" + Math.round(theDecimal * 100) / 100 
    var i = s.indexOf('.') 
    if (i < 0) { 
        return s + ".00" 
    } 
    var t = s.substring(0, i + 1) + s.substring(i + 1, i + 3) 
    if (i + 2 == s.length)     
        t += "0" 
    return t 
  }

出现错误的行：

if (i < 0) return s + ".00"

错误是：

error: expected (;)

有谁知道如何解决这个问题？

原文

The code is:

  function roundAmount(theDecimal) { 
    var s = "" + Math.round(theDecimal * 100) / 100 
    var i = s.indexOf('.') 
    if (i < 0) { 
        return s + ".00" 
    } 
    var t = s.substring(0, i + 1) + s.substring(i + 1, i + 3) 
    if (i + 2 == s.length)     
        t += "0" 
    return t 
  }

The line with the error:

if (i < 0) return s + ".00"

The error is:

error: expected (;)

does anyone know how to fix this?

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清风夜微凉 2024-08-04 22:06:21

关于您的脚本：

上面脚本中的问题是最后一个 if 语句执行一些操作，然后返回。操作后需要一个分号。

将来，作为良好的做法，请确保在每个有效语句后添加分号。这样就不会打扰你了。

将每一行视为一个想法，并将大括号视为将想法“分组”和“关联”在一起的方式。

下面是一个完整的想法，说“给我一个变量“i”，并给它值 1 + 2；

var i = 1 + 2;

下面是一个关于条件的完整想法，说“如果 i 是 3，则将 1 添加到 i”。 “add 1 to i”是它自己的想法，所以它需要一个分号，因为 IF 语句的大括号很特殊，因为它们在“完整的想法”之后不需要分号，只要你放一个“。块”（这就是大括号真正的作用），将思想括起来。

这意味着以下内容是有效的：

if( i == 3 ) {
    i = i + 1;
}

以下内容无效有效，因为 if 后面的分号结束了“思想”在 if 之前知道如果 i 等于 3 该怎么办：

if( i == 3 ) ; {
    i = i + 1;
}

有关基本 JavaScript 教程，请查看 W3Schools。

“一定有更好的方法吗？”

每当您发现自己对小数进行大量字符串操作时，最好问问自己“有一个更好的方法吗？”。

看起来您正在编写一个函数，将数字四舍五入到最接近的百分之一，同时显示两位小数点。有一种更简单的方法可以做到这一点。您可以四舍五入到最接近的百分之，然后让 javascript 输出定点数。

例子：

function roundAmount( theDecimal ) {
    //first round to the nearest hundredth
    //then return the value with two decimal places as a string
    return theDecimal.toFixed( 2 );
}

About your script:

The problem in the script above is that last if statement which does some operations followed by a return. You need a semi-colon after the operation.

In the future, as good practice, make sure to put a semi-colon after every valid statement. That way this won't bother you.

Think of each line as a thought, and curly braces as ways to "group" and "relate" thoughts together.

The below is a full thought that says "give me a variable "i" and give it the value 1 + 2;

var i = 1 + 2;

The below is a full thought about a condition that says "If i is 3 then add 1 to i". The thought "add 1 to i" is its own thought, so it needs a semicolon. Since the curlybraces for the IF statement are special in that they don't need a semi-colon after their "full thought" as long as you put a "block" (which is what curlybraces really make) after it, to enclose the thought.

This means the following is valid:

if( i == 3 ) {
    i = i + 1;
}

The following is not valid because the semi-colon after the if ends the "thought" before the if knows what to do if i equals 3:

if( i == 3 ) ; {
    i = i + 1;
}

For a basic JavaScript tutorial, check out W3Schools.

"There must be a better way?"

Any time you find yourself doing a lot of string operations on decmials, it's a good idea to ask yourself "is there a better way to do this?".

It looks like you're writing a function to round a number to the nearest hundredths while displaying two decimal points. There's a much easier way to do this. You can just round to the nearest hundredths and have javascript output the fixed point number.

Example:

function roundAmount( theDecimal ) {
    //first round to the nearest hundredth
    //then return the value with two decimal places as a string
    return theDecimal.toFixed( 2 );
}

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