blocks|key|2061321|text|Perl本身并不支持这个概念，但是有一些模块可以添加这个功能|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2061322|https://metacpan.org/pod/enum|offset|length|2061323|entityMap|0|LINK|mutability|MUTABLE|url^0|0|0|T|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|N|8|@]|9|@$D|O|E|P|1|Q]]|A|$]]|$1|F|3|-4|5|6|7|R|8|@]|9|@]|A|$]]]|G|$H|$5|I|J|K|A|$L|C]]]]

Perl doesn't support the concept natively but there are modules to add this functionality

<a href="https://metacpan.org/pod/enum" rel="noreferrer">https://metacpan.org/pod/enum</a>

blocks|key|1847372|text|你的方式已经足够了。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1847373|如果您碰巧使用Moose，也可以使用Moose::Util::TypeConstraints创建枚举。(你应该这样做。)|1847374|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|F|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|G|8|@]|9|@]|A|$]]|$1|D|3|-4|5|6|7|H|8|@]|9|@]|A|$]]]|E|$]]

Your way is more than adequate.

You can also create enums with Moose::Util::TypeConstraints, if you happen to be using Moose. (Which you should be.)

blocks|key|2061411|text|不，没有内置的枚举构造。Perl没有做很多严格的类型，所以我认为实际上没什么必要这样做。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2061412|在我看来，您使用的Readonly方法是可靠的。|offset|length|style|CODE|2061413|还有更传统的constant杂注。|2061414|use+constant+{
++++HOME+++=>+'Home',
++++WORK+++=>+'Work',
++++MOBILE+=>+'Mobile',
};

$phone_number->{type}+=+HOME;|code-block|syntax|javascript|2061415|在幕后，它为每个返回值的常量设置一个函数，如下所示。|2061416|sub+HOME+()+{+'Home'+}|2061417|除非你想利用这个特性，否则我会坚持使用Readonly，例如：|2061418|package+Phone::Type;

use+constant+{
++++HOME+=>+'Home',
++++#...
};

package+main;

print+Phone::Type->HOME,+"\n";|2061419|entityMap|0|LINK|mutability|MUTABLE|url|https://metacpan.org/pod/Readonly|1|http://perldoc.perl.org/constant.html|2^0|0|9|8|9|8|0|0|6|8|6|8|1|0|0|0|0|J|8|J|8|2|0|0^^$0|@$1|2|3|4|5|6|7|17|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|18|8|@$D|19|E|1A|F|G]]|9|@$D|1B|E|1C|1|1D]]|A|$]]|$1|H|3|I|5|6|7|1E|8|@$D|1F|E|1G|F|G]]|9|@$D|1H|E|1I|1|1J]]|A|$]]|$1|J|3|K|5|L|7|1K|8|@]|9|@]|A|$M|N]]|$1|O|3|P|5|6|7|1L|8|@]|9|@]|A|$]]|$1|Q|3|R|5|L|7|1M|8|@]|9|@]|A|$M|N]]|$1|S|3|T|5|6|7|1N|8|@$D|1O|E|1P|F|G]]|9|@$D|1Q|E|1R|1|1S]]|A|$]]|$1|U|3|V|5|L|7|1T|8|@]|9|@]|A|$M|N]]|$1|W|3|-4|5|6|7|1U|8|@]|9|@]|A|$]]]|X|$Y|$5|Z|10|11|A|$12|13]]|14|$5|Z|10|11|A|$12|15]]|16|$5|Z|10|11|A|$12|13]]]]

No, there isn't a built-in enum construct. Perl doesn't do a lot of strict typing, so I think there's actually little need for one.

In my opinion, the <a href="https://metacpan.org/pod/Readonly" rel="noreferrer"><code>Readonly</code></a> approach you used is solid.

There's also the more traditional <a href="http://perldoc.perl.org/constant.html" rel="noreferrer"><code>constant</code></a> pragma.

<pre><code>use constant {
 HOME =&gt; 'Home',
 WORK =&gt; 'Work',
 MOBILE =&gt; 'Mobile',
};

$phone_number-&gt;{type} = HOME;
</code></pre>

Behind the scenes, it sets up a function for each constant that returns the value, like so.

<pre><code>sub HOME () { 'Home' }
</code></pre>

I'd stick with <a href="https://metacpan.org/pod/Readonly" rel="noreferrer"><code>Readonly</code></a> unless you want to take advantage of that property, for example:

<pre><code>package Phone::Type;

use constant {
 HOME =&gt; 'Home',
 #...
};

package main;

print Phone::Type-&gt;HOME, "\n";
</code></pre>

blocks|key|2061451|text|Perl实际上有一个类似于C的枚举类型。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2061452|perldoc+enum|offset|length|style|CODE|2061453|例如：|2061454|use+enum+qw(HOME+WORK+MOBILE);|code-block|syntax|javascript|2061455|现在我们有：|2061456|HOME+==+0
WORK+==+1
MOBILE+==+2|2061457|您也可以自己设置索引：|2061458|use+enum+qw(HOME=0+WORK+MOBILE=10+FAX);|2061459|2061460|HOME+==+0
WORK+==+1
MOBILE+==+10
FAX+==+11|2061461|有关更多详细信息，请查看here。|2061462|请注意，并非所有版本的Perl都支持此功能。我知道v5.8.3不支持它，而v5.8.7支持。|2061463|entityMap|0|LINK|mutability|MUTABLE|url|https://metacpan.org/pod/enum|1^0|0|0|C|0|C|0|0|0|0|0|0|0|0|0|0|C|4|1|0|0^^$0|@$1|2|3|4|5|6|7|1C|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|1D|8|@$D|1E|E|1F|F|G]]|9|@$D|1G|E|1H|1|1I]]|A|$]]|$1|H|3|I|5|6|7|1J|8|@]|9|@]|A|$]]|$1|J|3|K|5|L|7|1K|8|@]|9|@]|A|$M|N]]|$1|O|3|P|5|6|7|1L|8|@]|9|@]|A|$]]|$1|Q|3|R|5|L|7|1M|8|@]|9|@]|A|$M|N]]|$1|S|3|T|5|6|7|1N|8|@]|9|@]|A|$]]|$1|U|3|V|5|L|7|1O|8|@]|9|@]|A|$M|N]]|$1|W|3|P|5|6|7|1P|8|@]|9|@]|A|$]]|$1|X|3|Y|5|L|7|1Q|8|@]|9|@]|A|$M|N]]|$1|Z|3|10|5|6|7|1R|8|@]|9|@$D|1S|E|1T|1|1U]]|A|$]]|$1|11|3|12|5|6|7|1V|8|@]|9|@]|A|$]]|$1|13|3|-4|5|6|7|1W|8|@]|9|@]|A|$]]]|14|$15|$5|16|17|18|A|$19|1A]]|1B|$5|16|17|18|A|$19|1A]]]]

Perl does in fact have an enum type like in C. Try this for details.

<a href="https://metacpan.org/pod/enum" rel="nofollow noreferrer" title="enum - C style enumerated types and bitmask flags in Perl"><code>perldoc enum</code></a>

For instance:

<pre><code>use enum qw(HOME WORK MOBILE);
</code></pre>

Now we have:

<pre><code>HOME == 0
WORK == 1
MOBILE == 2
</code></pre>

You can also set the indices yourself:

<pre><code>use enum qw(HOME=0 WORK MOBILE=10 FAX);
</code></pre>

Now we have:

<pre><code>HOME == 0
WORK == 1
MOBILE == 10
FAX == 11
</code></pre>

Look <a href="https://metacpan.org/pod/enum" rel="nofollow noreferrer" title="enum - C style enumerated types and bitmask flags in Perl">here</a> for more details.

Note that this isn't supported in every version of Perl. I know that v5.8.3 doesn't support it, while v5.8.7 does.

blocks|key|2061474|text|这对我很有效..。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2061475|use+constant+MYENUM+=>+qw(ZERO+ONE+TWO+THREE+FOUR);

BEGIN+{
++++eval+"use+constant+(MYENUM)[$_]+=>+$_;"+foreach+0..(MYENUM)-1;
}|code-block|syntax|javascript|2061476|然后，可以使用ZERO,+ONE,+TWO等作为常量，并使用(MYENUM)[$value]打印出它们的符号名称。|offset|length|style|CODE|2061477|entityMap^0|0|0|7|E|U|G|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|$]]

This worked nicely for me...

<pre><code>use constant MYENUM =&gt; qw(ZERO ONE TWO THREE FOUR);

BEGIN {
 eval "use constant (MYENUM)[$_] =&gt; $_;" foreach 0..(MYENUM)-1;
}
</code></pre>

You can then use <code>ZERO, ONE, TWO</code> etc as constants and print out their symbolic name using <code>(MYENUM)[$value]</code>.

Does Perl have an enumeration type that adheres to best practices, or maybe more importantly, does it need one?

The project I am working one uses strings all over the place to denote things that would typically use an Enum in a language like C#. For example, we have a set of phone numbers in an array of hashes, each associated with a phone type ("Home", "Work", "Mobile", etc.):

<pre><code>$phone_number-&gt;{type} = 'Home';
</code></pre>

Would it be sufficient to use a read-only set of variables here or should an Enum be used? I've found an <a href="http://search.cpan.org/perldoc/enum" rel="noreferrer"><code>enum</code> module on CPAN</a> but it appears to use bare words which violates one of the <a href="http://oreilly.com/catalog/9780596001735/" rel="noreferrer">Perl Best Practices</a>. My thinking on using <a href="http://search.cpan.org/perldoc/Readonly" rel="noreferrer">read-only variables</a> goes something like this:

<pre><code>use Readonly;

Readonly my $HOME =&gt; 'Home';
Readonly my $WORK =&gt; 'Work';
Readonly my $MOBILE =&gt; 'Mobile';

$phone_number-&gt;{type} = $HOME;
</code></pre>

Is this a good approach or is there a better way?

Does Perl have an enumeration type?

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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Perl是否有符合最佳实践的枚举类型，或者更重要的是，它是否需要一个枚举类型？我正在做的一个项目使用到处都是的字符串来表示在像C#这样的语言中通常使用枚举的东西。例如，我们在散列数组中有一组电话号码，每个号码都与一种电话类型("Home“、"Work”、"Mobile“等)相关联：$phone_number->{typ...

问Perl是否有枚举类型？
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