blocks|key|2940407|text|>>>+parseFloat(0.9999999.toFixed(4));
1
>>>+parseFloat(0.0009999999.toFixed(4));
0.001
>>>+parseFloat(0.0000009999999.toFixed(4));
0|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|2940408|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre><code>&gt;&gt;&gt; parseFloat(0.9999999.toFixed(4));
1
&gt;&gt;&gt; parseFloat(0.0009999999.toFixed(4));
0.001
&gt;&gt;&gt; parseFloat(0.0000009999999.toFixed(4));
0
</code></pre>

blocks|key|3154745|text|是的，有一种方法。使用parseFloat()。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|3154746|parseFloat((1.005).toFixed(15))+//==>+1.005
parseFloat((1.000000000).toFixed(15))+//==>+1|code-block|syntax|javascript|3154747|在这里看一个活生生的例子：http://jsfiddle.net/nayish/7JBJw/|3154748|entityMap|0|LINK|mutability|MUTABLE|url|http://jsfiddle.net/nayish/7JBJw/^0|B|C|0|0|D|X|0|0^^$0|@$1|2|3|4|5|6|7|U|8|@$9|V|A|W|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|X|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|Y|8|@]|D|@$9|Z|A|10|1|11]]|E|$]]|$1|M|3|-4|5|6|7|12|8|@]|D|@]|E|$]]]|N|$O|$5|P|Q|R|E|$S|T]]]]

Yes, there is a way. Use <code>parseFloat()</code>.

<pre><code>parseFloat((1.005).toFixed(15)) //==&gt; 1.005
parseFloat((1.000000000).toFixed(15)) //==&gt; 1
</code></pre>

See a live example here: <a href="http://jsfiddle.net/nayish/7JBJw/">http://jsfiddle.net/nayish/7JBJw/</a>

blocks|key|3154753|text|据我所知，您希望删除通过toFixed()获得的字符串中的尾随零。这是一个纯字符串操作：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|3154754|var+x+=+1.1230000;
var+y+=+x.toFixed(15).replace(/0%2B$/,+"");++//+==>+1.123|code-block|syntax|javascript|3154755|entityMap^0|C|9|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@$9|N|A|O|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|P|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|Q|8|@]|D|@]|E|$]]]|L|$]]

As I understand, you want to remove the trailing zeros in the string that you obtained via <code>toFixed()</code>. This is a pure string operation:

<pre><code>var x = 1.1230000;
var y = x.toFixed(15).replace(/0+$/, ""); // ==&gt; 1.123
</code></pre>

blocks|key|2940454|text|Number(n.toFixed(15))++or+%2B(n.toFixed(15))会将15位小数字符串转换为数字，去掉尾随的零。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|2940455|entityMap^0|0|16|0^^$0|@$1|2|3|4|5|6|7|H|8|@$9|I|A|J|B|C]]|D|@]|E|$]]|$1|F|3|-4|5|6|7|K|8|@]|D|@]|E|$]]]|G|$]]

<code>Number(n.toFixed(15)) or +(n.toFixed(15))</code> will convert the 15 place decimal string to a number, removing trailing zeroes.

blocks|key|258598|text|如果将返回值强制转换为一个数字，则这些尾随的零将被删除。这也没有parseFloat()那么冗长。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|258599|%2B(4.55555).toFixed(2);
//->+4.56

%2B(4).toFixed(2);
//->+4|code-block|syntax|javascript|258600|它使用unary+%2B+operator，所以如果使用它作为字符串操作的一部分，您需要在它之前有一个中缀%2B：var+n=0.9999999999999999;+console.log('output+'+%2B+%2Bn.toFixed(2));。仅供参考，字符串前面的一元%2B将其转换为数字。来自MDN:+Unary+%2B+can：|258601|258602|转换整数和浮点数的字符串表示，以及非字符串值true、false和null。支持十进制和十六进制("0x"-prefixed)格式的整数。支持负数(但不支持十六进制)。如果它不能解析一个特定值，它将计算为NaN。|blockquote|258603|258604|entityMap|0|LINK|mutability|MUTABLE|url|https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Operators/Arithmetic_Operators#Unary_plus_())^0|W|C|0|0|1H|1T|3|G|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|Z|8|@$9|10|A|11|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|12|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|13|8|@$9|14|A|15|B|C]]|D|@$9|16|A|17|1|18]]|E|$]]|$1|M|3|-4|5|6|7|19|8|@]|D|@]|E|$]]|$1|N|3|O|5|P|7|1A|8|@]|D|@]|E|$]]|$1|Q|3|-4|5|6|7|1B|8|@]|D|@]|E|$]]|$1|R|3|-4|5|6|7|1C|8|@]|D|@]|E|$]]]|S|$T|$5|U|V|W|E|$X|Y]]]]

If you cast the return value to a number, those trailing zeroes will be dropped. This is also less verbose than <code>parseFloat()</code> is.

<pre><code>+(4.55555).toFixed(2);
//-&gt; 4.56

+(4).toFixed(2);
//-&gt; 4
</code></pre>

This uses the <a href="https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Operators/Arithmetic_Operators#Unary_plus_()" rel="noreferrer">unary + operator</a>, so if using this as part of a string operation you need to have an infix + before it: <code>var n=0.9999999999999999; console.log('output ' + +n.toFixed(2));</code>. FYI a unary + in front of a string converts it to a Number. From MDN: Unary + can:

<blockquote>
 convert string representations of integers and floats, as well
 as the non-string values true, false, and null. Integers in both
 decimal and hexadecimal ("0x"-prefixed) formats are supported.
 Negative numbers are supported (though not for hex). If it cannot
 parse a particular value, it will evaluate to NaN.
</blockquote>

blocks|key|2940499|text|所有这些都没有真正得到我想要的基于问题标题的结果，例如，5.00等于5，5.10等于5.1。我的解决方案如下：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2940500|num.toFixed(places).replace(/\.?0%2B$/,+'')

'5.00'.replace(/\.?0%2B$/,+'')+//+5
'5.10'.replace(/\.?0%2B$/,+'')+//+5.1
'5.0000001'.replace(/\.?0%2B$/,+'')+//+5.0000001
'5.0001000'.replace(/\.?0%2B$/,+'')+//+5.0001|code-block|syntax|javascript|2940501|注意:正则表达式仅在places+>+0|offset|length|style|CODE|2940502|P.S.+https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number/toFixed|2940503|entityMap|0|LINK|mutability|MUTABLE|url|https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number/toFixed^0|0|0|A|A|0|5|2N|0|0^^$0|@$1|2|3|4|5|6|7|W|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|X|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|Y|8|@$I|Z|J|10|K|L]]|9|@]|A|$]]|$1|M|3|N|5|6|7|11|8|@]|9|@$I|12|J|13|1|14]]|A|$]]|$1|O|3|-4|5|6|7|15|8|@]|9|@]|A|$]]]|P|$Q|$5|R|S|T|A|$U|V]]]]

None of these really got me what I was looking for based on the question title, which was, for example, for 5.00 to be 5 and 5.10 to be 5.1. My solution was as follows:

<pre><code>num.toFixed(places).replace(/\.?0+$/, '')

'5.00'.replace(/\.?0+$/, '') // 5
'5.10'.replace(/\.?0+$/, '') // 5.1
'5.0000001'.replace(/\.?0+$/, '') // 5.0000001
'5.0001000'.replace(/\.?0+$/, '') // 5.0001
</code></pre>

Note: The regex only works if <code>places &gt; 0</code>

P.S. <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number/toFixed" rel="nofollow">https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number/toFixed</a>

blocks|key|3154855|text|有一种更好的方法，既能保持精度，又能去掉零点。这需要一个输入数字，通过某种魔术的强制转换，它将把所有尾随的零都去掉。我发现16是我的精度极限，如果你不把卫星放在冥王星上，这是相当好的。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3154856|function+convertToFixed(inputnum)
{

++++++var+mynum+=+inputnum.toPrecision(16);
//If+you+have+a+string+already+ignore+this+first+line+and+change+mynum.toString+to+the+inputnum

++++++var+mynumstr+=+mynum.toString();
++++return+parseFloat(mynumstr);
++++}
++++alert(convertToFixed(6.6/6));|code-block|syntax|javascript|3154857|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

There is a better method which keeps precision and also strips the zeros. This takes an input number and through some magic of casting will pull off any trailing zeros. I've found 16 to be the precision limit for me which is pretty good should you not be putting a satellite on pluto. 

<pre><code>function convertToFixed(inputnum)
{

 var mynum = inputnum.toPrecision(16);
//If you have a string already ignore this first line and change mynum.toString to the inputnum

 var mynumstr = mynum.toString();
 return parseFloat(mynumstr);
 }
 alert(convertToFixed(6.6/6));
</code></pre>

blocks|key|2940580|text|toFixed()+method使用定点表示法对number进行格式化，并返回string。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|2940581|它应用了的半舍五入策略。|BOLD|2940582|(0.124).toFixed(2);+//+returns+0.12
(0.125).toFixed(2);+//+returns+0.13|code-block|syntax|javascript|2940583|正如您所描述的，有时它确实还会导致(可能不必要的)尾随零。|2940584|(0.001).toFixed(2);+//+returns+0.00|2940585|你可能不想去掉那些尾随的零，基本上你可以把它转换回一个number。有很多方法可以做到这一点。|2940586|%2B(0.001).toFixed(2);+//+the+shortest|2940587|有关将字符串转换为数字的不同方法的概述，请查看this+check，其中有一些很好的答案。|2940588|entityMap|0|LINK|mutability|MUTABLE|url|https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number/toFixed|1|https://stackoverflow.com/questions/12227594/which-is-better-numberx-or-parsefloatx^0|0|9|O|6|13|6|0|G|0|0|4|5|0|0|0|0|R|6|0|0|N|4|1|0^^$0|@$1|2|3|4|5|6|7|17|8|@$9|18|A|19|B|C]|$9|1A|A|1B|B|C]|$9|1C|A|1D|B|C]]|D|@$9|1E|A|1F|1|1G]]|E|$]]|$1|F|3|G|5|6|7|1H|8|@$9|1I|A|1J|B|H]]|D|@]|E|$]]|$1|I|3|J|5|K|7|1K|8|@]|D|@]|E|$L|M]]|$1|N|3|O|5|6|7|1L|8|@]|D|@]|E|$]]|$1|P|3|Q|5|K|7|1M|8|@]|D|@]|E|$L|M]]|$1|R|3|S|5|6|7|1N|8|@$9|1O|A|1P|B|C]]|D|@]|E|$]]|$1|T|3|U|5|K|7|1Q|8|@]|D|@]|E|$L|M]]|$1|V|3|W|5|6|7|1R|8|@]|D|@$9|1S|A|1T|1|1U]]|E|$]]|$1|X|3|-4|5|6|7|1V|8|@]|D|@]|E|$]]]|Y|$Z|$5|10|11|12|E|$13|14]]|15|$5|10|11|12|E|$13|16]]]]

The <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number/toFixed" rel="nofollow noreferrer"><code>toFixed()</code> method</a> formats a <code>number</code> using fixed-point notation, and returns a <code>string</code>. 

It applies a half-up rounding strategy.

<pre><code>(0.124).toFixed(2); // returns 0.12
(0.125).toFixed(2); // returns 0.13
</code></pre>

As you described, it will indeed also result in (potentially unnecessary) trailing zeroes sometimes.

<pre><code>(0.001).toFixed(2); // returns 0.00
</code></pre>

You may not want to get rid of those trailing zeroes, essentially you could just convert it back to a <code>number</code>. There are many ways to do this.

<pre><code>+(0.001).toFixed(2); // the shortest
</code></pre>

For an overview, of the different methods to convert strings to numbers, please check <a href="https://stackoverflow.com/questions/12227594/which-is-better-numberx-or-parsefloatx">this</a> question, which has some excellent answers.

blocks|key|255399|text|我发现的最有效的下注方法如下|type|unstyled|depth|inlineStyleRanges|entityRanges|data|255400|function+round(value,+decimals)+{
++return+Number(Math.round(value%2B'e'%2Bdecimals)%2B'e-'%2Bdecimals);
}|code-block|syntax|javascript|255401|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

most efficient and bets method I found is below
<pre><code>function round(value, decimals) {
 return Number(Math.round(value+'e'+decimals)+'e-'+decimals);
}
</code></pre>

Here's the scenario: I'm getting <code>.9999999999999999</code> when I should be getting <code>1.0</code>. 
I can afford to lose a decimal place of precision, so I'm using <code>.toFixed(15)</code>, which kind of works.

The rounding works, but the problem is that I'm given <code>1.000000000000000</code>. 
Is there a way to round to a number of decimal places, but strip extra whitespace?

Note: <code>.toPrecision</code> isn't what I want; I only want to specify how many numbers after the decimal point. 
Note 2: I can't just use <code>.toPrecision(1)</code> because I need to keep the high precision for numbers that actually have data after the decimal point. Ideally, there would be exactly as many decimal places as necessary (up to 15).

JavaScript: Round to a number of decimal places, but strip extra zeros

这是一个场景:我在应该得到1.0的时候却得到了.9999999999999999。我可以承受损失一个小数位的精度，所以我使用.toFixed(15)，这是一种有效的方法。四舍五入可以工作，但问题是我得到的是1.000000000000000。有没有办法舍入到小数点后的几位，但去掉额外的空格？注意：.toPrecisio...

问JavaScript:四舍五入到小数位数，但去掉多余的零
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问JavaScript:四舍五入到小数位数，但去掉多余的零
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