Perl中的$ this，@ that和％those有什么区别? [英] What is the difference between `$this`, `@that`, and `%those` in Perl?

问题描述

Perl中$this，@that和%those有什么区别?

What is the difference between $this, @that, and %those in Perl?

推荐答案

Perl信号有用的助记符是:

A useful mnemonic for Perl sigils are:

• $ calar
• @rray
• ％ash

马特鳟鱼对 blog.fogus.me 我认为很有用，因此已在下面粘贴:

Matt Trout wrote a great comment on blog.fogus.me about Perl sigils which I think is useful so have pasted below:

实际上，perl信号不表示变量类型-它们表示共轭-$是"the"，@是 这些"，％"是映射表" –变量类型通过[]或{}表示.您可以通过以下方式看到此信息:

Actually, perl sigils don’t denote variable type – they denote conjugation – $ is ‘the’, @ is ‘these’, % is ‘map of’ or so – variable type is denoted via [] or {}. You can see this with:

my $foo = 'foo';
my @foo = ('zero', 'one', 'two');
my $second_foo = $foo[1];
my @first_and_third_foos = @foo[0,2];
my %foo = (key1 => 'value1', key2 => 'value2', key3 => 'value3');
my $key2_foo = $foo{key2};
my ($key1_foo, $key3_foo) = @foo{'key1','key3'};

因此，在浏览Perl代码时看着标记会告诉您您要去-get-而不是 比您的操作要多得多.

so looking at the sigil when skimming perl code tells you what you’re going to -get- rather than what you’re operating on, pretty much.

诚然，在您习惯之前，这确实令人困惑，但是一旦您习惯了它， 它是在浏览代码时吸收信息的非常有用的工具.

This is, admittedly, really confusing until you get used to it, but once you -are- used to it it can be an extremely useful tool for absorbing information while skimming code.

您当然仍然很讨厌它，但这是一个有趣的概念，我 认为您可能更讨厌实际发生的事情，而不是讨厌自己认为的事情 继续:)

You’re still perfectly entitled to hate it, of course, but it’s an interesting concept and I figure you might prefer to hate what’s -actually- going on rather than what you thought was going on :)

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