如果由于任何原因(比如涉及到金钱浮动)不能使用float，并且已经从表示正确数字的字符串开始，您可以发现这个解决方案很方便。它将表示数字的字符串转换为表示数字的字符串，后面不带零。

function removeTrailingZeroes( strAmount ) {
    // remove all trailing zeroes in the decimal part
    var strDecSepCd = '.'; // decimal separator
    var iDSPosition = strAmount.indexOf( strDecSepCd ); // decimal separator positions
    if ( iDSPosition !== -1 ) {
        var strDecPart = strAmount.substr( iDSPosition ); // including the decimal separator

        var i = strDecPart.length - 1;
        for ( ; i >= 0 ; i-- ) {
            if ( strDecPart.charAt(i) !== '0') {
                break;
            }
        }

        if ( i=== 0 ) {
            return strAmount.substring(0, iDSPosition);
        } else {
            // return INTPART and DS + DECPART including the rightmost significant number
            return strAmount.substring(0, iDSPosition) + strDecPart.substring(0,i + 1);
        }
    }

    return strAmount;
}

所以你想

var x = 1.234000; // to become 1.234
var y = 1.234001; // stays 1.234001

没有附加条件，只需尝试Number()。

Var x = 1.234000， //变成1.234 Y = 1.234001， //保持1.234001 x_ =数字(x)， y_ =数字(y); y_ console.log(间);

当Django在文本字段中显示十进制类型的值时，我也需要解决这个问题。例如，当'1'是值时。它会显示“1.00000000”。如果'1.23'是值，它将显示'1.23000000'(在'decimal_places'设置为8的情况下)

使用parseFloat对我来说不是一个选项，因为它可能不会返回完全相同的值。toFixed不是一个选项，因为我不想四舍五入任何东西，所以我创建了一个函数:

function removeTrailingZeros(value) {
    value = value.toString();

    # if not containing a dot, we do not need to do anything
    if (value.indexOf('.') === -1) {
        return value;
    }

    # as long as the last character is a 0 or a dot, remove it
    while((value.slice(-1) === '0' || value.slice(-1) === '.') && value.indexOf('.') !== -1) {
        value = value.substr(0, value.length - 1);
    }
    return value;
}

我首先使用了matti-lyra和gary的答案的组合:

r=(+n).toFixed(4).replace(/\.0+$/,'')

结果:

1234870.98762341:“1234870.9876” 1230009100:“1230009100” 0.0012234:“0.0012” 0.1200234:“0.12” 0.000001231:“0” 0.10001:“0.1000” "asdf": "NaN"(所以没有运行时错误)

有点问题的情况是0.10001。我最终使用了这个更长的版本:

    r = (+n).toFixed(4);
    if (r.match(/\./)) {
      r = r.replace(/\.?0+$/, '');
    }

1234870.98762341:“1234870.9876” 1230009100:“1230009100” 0.0012234:“0.0012” 0.1200234:“0.12” 0.000001231:“0” 0.10001:“0.1” "asdf": "NaN"(所以没有运行时错误)

更新:这是加里的新版本(见评论):

r=(+n).toFixed(4).replace(/([0-9]+(\.[0-9]+[1-9])?)(\.?0+$)/,'$1')

这将得到与上面相同的结果。

如果我们有一个数字的s字符串表示形式，例如我们可以使用number的.toFixed(digits)方法(或任何其他方法)来获得，那么为了从s字符串中删除不重要的末尾零，我们可以使用:

s.replace(/(\.0*|(?<=(\..*))0*)$/, '')

/**********************************
 * Results for various values of s:
 **********************************
 *
 * "0" => 0
 * "0.000" => 0
 * 
 * "10" => 10
 * "100" => 100
 * 
 * "0.100" => 0.1
 * "0.010" => 0.01
 * 
 * "1.101" => 1.101
 * "1.100" => 1.1
 * "1.100010" => 1.10001
 * 
 * "100.11" => 100.11
 * "100.10" => 100.1
 */

replace()中使用的正则表达式解释如下:

In the first place please pay the attention to the | operator inside the regular expression, which stands for "OR", so, the replace() method will remove from s two possible kinds of substring, matched either by the (\.0*)$ part OR by the ((?<=(\..*))0*)$ part. The (\.0*)$ part of regex matches a dot symbol followed by all the zeros and nothing else till to the end of the s. This might be for example 0.0 (.0 is matched & removed), 1.0 (.0 is matched & removed), 0.000 (.000 is matched & removed) or any similar string with all the zeros after the dot, so, all the trailing zeros and the dot itself will be removed if this part of regex will match. The ((?<=(\..*))0*)$ part matches only the trailing zeros (which are located after a dot symbol followed by any number of any symbol before start of the consecutive trailing zeros). This might be for example 0.100 (trailing 00 is matched & removed), 0.010 (last 0 is matched & removed, note that 0.01 part do NOT get matched at all thanks to the "Positive Lookbehind Assertion", i.e. (?<=(\..*)), which is in front of 0* in this part of regex), 1.100010 (last 0 is matched & removed), etc. If neither of the two parts of expression will match, nothing gets removed. This might be for example 100 or 100.11, etc. So, if an input does not have any trailing zeros then it stays unchanged.

更多使用.toFixed(数字)的例子(在下面的例子中使用了字面值“1000.1010”，但我们可以假设变量):

let digits = 0; // Get `digits` from somewhere, for example: user input, some sort of config, etc.

(+"1000.1010").toFixed(digits).replace(/(\.0*|(?<=(\..*))0*)$/, '');
// Result: '1000'

(+"1000.1010").toFixed(digits = 1).replace(/(\.0*|(?<=(\..*))0*)$/, '');
// Result: '1000.1'


(+"1000.1010").toFixed(digits = 2).replace(/(\.0*|(?<=(\..*))0*)$/, '');
// Result: '1000.1'


(+"1000.1010").toFixed(digits = 3).replace(/(\.0*|(?<=(\..*))0*)$/, '');
// Result: '1000.101'


(+"1000.1010").toFixed(digits = 4).replace(/(\.0*|(?<=(\..*))0*)$/, '');
// Result: '1000.101'


(+"1000.1010").toFixed(digits = 5).replace(/(\.0*|(?<=(\..*))0*)$/, '');
// Result: '1000.101'

(+"1000.1010").toFixed(digits = 10).replace(/(\.0*|(?<=(\..*))0*)$/, '');
// Result: '1000.101'

要使用replace()中使用的上述正则表达式，我们可以访问:https://regex101.com/r/owj9fz/1

在阅读了所有的答案和评论后，我得出了这样的结论:

function isFloat(n) {
    let number = (Number(n) === n && n % 1 !== 0) ? eval(parseFloat(n)) : n;
    return number;
}

我知道使用eval在某种程度上是有害的，但这帮助了我很多。

So:

isFloat(1.234000);     // = 1.234;
isFloat(1.234001);     // = 1.234001
isFloat(1.2340010000); // = 1.234001

如果你想限制小数点后的位置，可以使用toFixed()。

let number = (Number(n) === n && n % 1 !== 0) ? eval(parseFloat(n).toFixed(3)) : n;

就是这样。