blocks|key|458836|text|据我所知有4种方法可以做到这一点。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|458837|Number(x);
parseInt(x,+10);
parseFloat(x);
%2Bx;|code-block|syntax|javascript|458838|通过我所做的这个快速测试，它实际上取决于浏览器。|458839|http://jsperf.com/best-of-string-to-number-conversion/2|offset|length|458840|Implicit在3种浏览器上都是最快的，但它使代码难以阅读…所以，选择你喜欢的东西吧！|style|CODE|458841|entityMap|0|LINK|mutability|MUTABLE|url^0|0|0|0|0|1J|0|0|0|8|0^^$0|@$1|2|3|4|5|6|7|X|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|Y|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|Z|8|@]|9|@]|A|$]]|$1|I|3|J|5|6|7|10|8|@]|9|@$K|11|L|12|1|13]]|A|$]]|$1|M|3|N|5|6|7|14|8|@$K|15|L|16|O|P]]|9|@]|A|$]]|$1|Q|3|-4|5|6|7|17|8|@]|9|@]|A|$]]]|R|$S|$5|T|U|V|A|$W|J]]]]

There are 4 ways to do it as far as I know.

<pre><code>Number(x);
parseInt(x, 10);
parseFloat(x);
+x;
</code></pre>

By this quick test I made, it actually depends on browsers.

<a href="http://jsperf.com/best-of-string-to-number-conversion/2" rel="noreferrer">http://jsperf.com/best-of-string-to-number-conversion/2</a>

<code>Implicit</code> marked the fastest on 3 browsers, but it makes the code hard to read… So choose whatever you feel like it!

blocks|key|242025|text|将字符串转换为整数的一种快速方法是使用按位或，如下所示：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|242026|x+%7C+0|code-block|syntax|javascript|242027|虽然这取决于它是如何实现的，但理论上它应该相对较快(至少和%2Bx一样快)，因为它将首先将x转换为一个数字，然后执行一个非常有效的or。|offset|length|style|CODE|242028|entityMap^0|0|0|T|2|17|1|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|Q|8|@$I|R|J|S|K|L]|$I|T|J|U|K|L]]|9|@]|A|$]]|$1|M|3|-4|5|6|7|V|8|@]|9|@]|A|$]]]|N|$]]

A fast way to convert strings to an integer is to use a bitwise or, like so: 

<pre><code>x | 0
</code></pre>

While it depends on how it is implemented, in theory it should be relatively fast (at least as fast as <code>+x</code>) since it will first cast <code>x</code> to a number and then perform a very efficient or.

blocks|key|242053|text|这可能不是那么快，但有一个额外的好处，确保你的数字至少是一个特定值(例如0)，或者至多是一个特定值：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|242054|Math.max(input,+0);|code-block|syntax|javascript|242055|如果你需要确保一个最小值，通常你会这样做|242056|var+number+=+Number(input);
if+(number+<+0)+number+=+0;|242057|Math.max(...,+0)使您不必编写两条语句。|offset|length|style|CODE|242058|entityMap^0|0|0|0|0|0|G|0^^$0|@$1|2|3|4|5|6|7|S|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|T|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|U|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|V|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|W|8|@$M|X|N|Y|O|P]]|9|@]|A|$]]|$1|Q|3|-4|5|6|7|Z|8|@]|9|@]|A|$]]]|R|$]]

This is probably not that fast, but has the added benefit of making sure your number is at least a certain value (e.g. 0), or at most a certain value:

<pre><code>Math.max(input, 0);
</code></pre>

If you need to ensure a minimum value, usually you'd do

<pre><code>var number = Number(input);
if (number &lt; 0) number = 0;
</code></pre>

<code>Math.max(..., 0)</code> saves you from writing two statements.

blocks|key|242071|text|在字符串前面加上%2B运算符。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|242072|console.log(%2B'a')+//+NaN
console.log(%2B'1')+//+1
console.log(%2B1)+//+1|code-block|syntax|javascript|242073|entityMap^0|8|1|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|$]]

Prefix the string with the <code>+</code> operator.

<pre><code>console.log(+'a') // NaN
console.log(+'1') // 1
console.log(+1) // 1
</code></pre>

blocks|key|242105|text|我发现num+*+1非常简单、清晰，并且适用于整数和浮点数……|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|242106|entityMap^0|3|7|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|$]]

I find that <code>num * 1</code> is simple, clear, and works for integers and floats...

blocks|key|242155|text|您可以尝试使用UnitOf，这是我们刚刚正式发布的度量和数据类型转换库！UnitOf非常快，体积小，在转换任何数据类型时都很有效，而不会抛出错误或null/undefined。当转换失败时，将返回您定义的默认值或UnitOf的默认值。|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|242156|//One+liner+examples
UnitOf.DataType("12.5").toFloat();+//12.5+of+type+Float+is+returned.+0+would+be+returned+if+conversion+failed.
UnitOf.DataType("Not+A+Num").toInt(10);+//10+of+type+Int+is+returned+as+the+conversion+failed.

//Or+as+a+variable
var+unit+=+UnitOf.DataType("12.5");
unit.toInt(5);+//12.5+of+type+Float+is+returned.+5+would+be+returned+if+the+conversion+failed.
unit.toFloat(8);+//+12+of+type+Int+is+returned.+8+would+be+returned+if+the+conversion+failed.|code-block|syntax|javascript|242157|entityMap|0|LINK|mutability|MUTABLE|url|https://digidemic.github.io/UnitOf/^0|7|6|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@$A|R|B|S|1|T]]|C|$]]|$1|D|3|E|5|F|7|U|8|@]|9|@]|C|$G|H]]|$1|I|3|-4|5|6|7|V|8|@]|9|@]|C|$]]]|J|$K|$5|L|M|N|C|$O|P]]]]

You can try using <a href="https://digidemic.github.io/UnitOf/" rel="nofollow noreferrer">UnitOf</a>, a measurement and data type conversion library we just officially released! UnitOf is super fast, small in size, and efficient at converting any data type without ever throwing an error or null/undefined. Default values you define or UnitOf's defaults are returned when a conversion is unsuccessful.

<pre><code>//One liner examples
UnitOf.DataType("12.5").toFloat(); //12.5 of type Float is returned. 0 would be returned if conversion failed.
UnitOf.DataType("Not A Num").toInt(10); //10 of type Int is returned as the conversion failed.

//Or as a variable
var unit = UnitOf.DataType("12.5");
unit.toInt(5); //12.5 of type Float is returned. 5 would be returned if the conversion failed.
unit.toFloat(8); // 12 of type Int is returned. 8 would be returned if the conversion failed.
</code></pre>

blocks|key|459130|text|最快的方法是使用-0：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|459131|const+num+=+"12.34"+-+0;|code-block|syntax|javascript|459132|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|$]]

The fastest way is using -0:

<pre><code>const num = "12.34" - 0;
</code></pre>

Any number, it's number. String looks like a number, it's number. Everything else, it goes NaN.

<pre><code>'a' =&gt; NaN
'1' =&gt; 1
1 =&gt; 1
</code></pre>

What's the fastest way to convert String to Number in JavaScript?

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

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任何数字，都是数字。字符串看起来像一个数字，它就是数字。其他所有东西，它都是NaN。'a' => NaN'1' => 11 => 1

问在JavaScript中将字符串转换为数字的最快方法是什么？
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问在JavaScript中将字符串转换为数字的最快方法是什么？
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