Perl 使用特殊字符 & [英] Perl using the special character &
问题描述
我有一个小问题.我正在阅读一些代码,因为我的学校没有教我任何关于 perl 编程的有用信息,所以我在这里问你们.我看到在某些 perl 程序中经常使用此行:
I had a small question. I was reading some code and as my school didn't teach me anything useful about perl programming, I am here to ask you people. I see this line being used a lot in some perl programs:
$variable = &something();
我不知道 &
符号在这里意味着什么,因为我从未在 perl 中说过.而 something
是一个子程序(我猜).它通常说一个名字,有时它也有像函数一样的参数.谁能告诉我 &
在这里代表什么以及 something
是什么.
I don't know what the &
sign means here as I never say it in perl. And the something
is a subroutine ( I am guessing). It usually says a name and it has arguments like a function too sometimes. Can someone tell me what &
stands for here and what that something
is all the time.
该变量接受某种返回值,然后用于检查某些条件,这让我认为它是一个子程序.但为什么是 &
?
The variable takes in some sort of returned value and is then used to check some conditions, which makes me think it is a subroutine. But still why the &
?
谢谢
推荐答案
在旧版本的 perl 中,&
用于调用子程序.现在这不是必需的,\&
主要用于将 reference
带入子程序,
In older versions of perl &
was used to call subroutines. Now this is not necessary and \&
is mostly used to take a reference
to subroutine,
my $sub_ref = \&subroutine;
或者忽略函数原型(http://perldoc.perl.org/perlsub.html#原型)
除了用于引用子程序的 &
是 bitwise and
运算符,
Other than for referencing subroutines &
is bitwise and
operator,
http://perldoc.perl.org/perlop.html#Bitwise-And
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