blocks|key|1684777|text|如果String#ord在1.9中不存在，那么它在2.0中存在：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1684778|"A".ord+#=>+65|code-block|syntax|javascript|1684779|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|$]]

If String#ord didn't exist in 1.9, it does in 2.0:

<pre><code>"A".ord #=&gt; 65
</code></pre>

blocks|key|1469493|text|在Ruby+1.8系列及之前的版本中，以下代码都将生成65+(对于ASCII)：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1469494|puts+?A
'A'[0]|code-block|syntax|javascript|1469495|在Ruby+1.9中，这一行为发生了变化，以上两种情况都将生成"A“。在Ruby+1.9中，正确的方法是：|1469496|'A'[0].ord|1469497|不幸的是，Ruby1.8中不存在ord方法。|offset|length|style|CODE|1469498|entityMap^0|0|0|0|0|G|3|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|$]]

In Ruby up to and including the 1.8 series, the following will both produce 65 (for ASCII):

<pre><code>puts ?A
'A'[0]
</code></pre>

The behavior has changed in Ruby 1.9, both of the above will produce "A" instead. The correct way to do this in Ruby 1.9 is:

<pre><code>'A'[0].ord
</code></pre>

Unfortunately, the <code>ord</code> method doesn't exist in Ruby 1.8.

blocks|key|1469345|text|尝试：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1469346|'A'.unpack('c')|code-block|syntax|javascript|1469347|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|$]]

Try:

<pre><code>'A'.unpack('c')
</code></pre>

blocks|key|1469650|text|这是在通过RFC组装一个纯Ruby版本的Stringprep时遇到的。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1469651|请注意，chr在0,255之外出现故障，请改用1.9.x+-+2.1.x便携替换：|offset|length|style|CODE|1469652|[22]+pry(main)>+"\u0221".ord.chr
RangeError:+545+out+of+char+range
from+(pry):2:in+'chr'
[23]+pry(main)>+x+=+"\u0221".unpack('U')[0]
=>+545
[24]+pry(main)>+[x].pack('U')
=>+"ȡ"
[25]+pry(main)>|code-block|syntax|javascript|1469653|entityMap^0|0|4|3|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|P|8|@$D|Q|E|R|F|G]]|9|@]|A|$]]|$1|H|3|I|5|J|7|S|8|@]|9|@]|A|$K|L]]|$1|M|3|-4|5|6|7|T|8|@]|9|@]|A|$]]]|N|$]]

Just came across this while putting together a pure Ruby version of Stringprep via RFCs.

Beware that <code>chr</code> fails outside [0,255], instead use 1.9.x - 2.1.x portable replacements:

<pre><code>[22] pry(main)&gt; "\u0221".ord.chr
RangeError: 545 out of char range
from (pry):2:in 'chr'
[23] pry(main)&gt; x = "\u0221".unpack('U')[0]
=&gt; 545
[24] pry(main)&gt; [x].pack('U')
=&gt; "ȡ"
[25] pry(main)&gt;
</code></pre>

blocks|key|1469396|text|此外，如果字符串中有char，并且您希望在不使用循环的情况下对其进行解码：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1469397|puts+'Az'[0]
=>+65
puts+'Az'[1]
=>+122|code-block|syntax|javascript|1469398|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|$]]

Additionally, if you have the char in a string and you want to decode it without a loop: 

<pre><code>puts 'Az'[0]
=&gt; 65
puts 'Az'[1]
=&gt; 122
</code></pre>

blocks|key|1684814|text|你可以拥有这些：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1684815|65.chr.ord
'a'.ord.chr|code-block|syntax|javascript|1684816|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|$]]

You can have these:

<pre><code>65.chr.ord
'a'.ord.chr
</code></pre>

blocks|key|1469691|text|如果您不介意从数组中提取值，可以使用"A".bytes|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1469692|entityMap^0|I|9|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|$]]

If you don't mind pulling the values out of an array, you can use <code>"A".bytes</code>

blocks|key|1469737|text|我正在为1.8.6和1.9.3编写代码，但我无法让这些解决方案中的任何一个在这两个环境中工作：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1469738|然而，我遇到了另一个解决方案：http://smajnr.net/2009/12/ruby-1-8-nomethoderror-undefined-method-ord-for-string.html|offset|length|1469739|这对我来说也不起作用，但我根据自己的用途对其进行了调整：|1469740|​|1469741|unless+"".respond_to?(:ord)
++class+Fixnum
++++def+ord
++++++return+self
++++end
++end
end|code-block|syntax|javascript|1469742|1469743|这样做之后，下面的代码就可以在这两种环境中工作了|1469744|1469745|'A'[0].ord|1469746|1469747|entityMap|0|LINK|mutability|MUTABLE|url|http://smajnr.net/2009/12/ruby-1-8-nomethoderror-undefined-method-ord-for-string.html^0|0|F|2D|0|0|0|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|13|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|14|8|@]|9|@$D|15|E|16|1|17]]|A|$]]|$1|F|3|G|5|6|7|18|8|@]|9|@]|A|$]]|$1|H|3|I|5|6|7|19|8|@]|9|@]|A|$]]|$1|J|3|K|5|L|7|1A|8|@]|9|@]|A|$M|N]]|$1|O|3|I|5|6|7|1B|8|@]|9|@]|A|$]]|$1|P|3|Q|5|6|7|1C|8|@]|9|@]|A|$]]|$1|R|3|I|5|6|7|1D|8|@]|9|@]|A|$]]|$1|S|3|T|5|L|7|1E|8|@]|9|@]|A|$M|N]]|$1|U|3|I|5|6|7|1F|8|@]|9|@]|A|$]]|$1|V|3|-4|5|6|7|1G|8|@]|9|@]|A|$]]]|W|$X|$5|Y|Z|10|A|$11|12]]]]

I'm writing code for 1.8.6 and 1.9.3 and I couldn't get any of these solutions to work in both environments :(

However, I came across another solution:
<a href="http://smajnr.net/2009/12/ruby-1-8-nomethoderror-undefined-method-ord-for-string.html" rel="nofollow">http://smajnr.net/2009/12/ruby-1-8-nomethoderror-undefined-method-ord-for-string.html</a>

That didn't work for me either but I adapted it for my use:

<div class="snippet" data-lang="js" data-hide="false">
<div class="snippet-code">
<pre class="snippet-code-html lang-html prettyprint-override"><code>unless "".respond_to?(:ord)
 class Fixnum
 def ord
 return self
 end
 end
end</code></pre>
</div>
</div>


Having done that, then the following will work in both environments

<div class="snippet" data-lang="js" data-hide="false">
<div class="snippet-code">
<pre class="snippet-code-html lang-html prettyprint-override"><code>'A'[0].ord</code></pre>
</div>
</div>

In many languages there's a pair of functions, <code>chr()</code> and <code>ord()</code>, which convert between numbers and character values. In some languages, <code>ord()</code> is called <code>asc()</code>.

Ruby has <code>Integer#chr</code>, which works great:

<pre><code>&gt;&gt; 65.chr
A
</code></pre>

Fair enough. But how do you go the other way?

<pre><code>"A".each_byte do |byte|
 puts byte
end
</code></pre>

prints:

<pre><code>65
</code></pre>

and that's pretty close to what I want. But I'd really rather avoid a loop -- I'm looking for something short enough to be readable when declaring a <code>const</code>.

What's the opposite of chr() in Ruby?

在许多语言中，有一对函数chr()和ord()，它们在数字和字符值之间进行转换。在某些语言中，ord()被称为asc()。Ruby有Integer#chr，它工作得很好：>> 65.chrA当然可以。但是你怎么走另一条路呢？"A".each_byte do |byte|   puts byteend打印：65这和我想要的非常接近。但我确实希望避免循环--在声明const时，我想要的是足够短以便可读

问Ruby中的chr()的对立面是什么？
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