如何在Perl中迭代/解引用子例程引用数组? [英] How do I iterate over/dereference an array of subroutine refs in Perl?

问题描述

我正在尝试弄清如何遍历一系列子例程引用.

I’m trying to figure out how to iterate over an array of subroutine refs.

此语法有什么问题?

use strict;
use warnings;

sub yell { print "Ahh!\n"; }
sub kick { print "Boot!\n"; }
sub scream { print "Eeek!\n"; }

my @routines = (\&yell, \&kick, \&scream);
foreach my $routine_ref (@routines) {
  my &routine = &{$routine_ref};
  &routine;
}

提前谢谢！

推荐答案

在您的foreach循环中，以下是语法错误:

In your foreach loop, the following is a syntax error:

my &routine;

您的变量$routine_ref已经有对该子例程的引用，因此此时您需要做的就是调用它:

Your variable $routine_ref already has a reference to the subroutine, so all you need to do at that point is call it:

for my $routine_ref (@routines) {
    &{$routine_ref};
}

与Perl一样，实现这一目标的方法不止一种."例如，如果这些子例程中的任何一个都带有参数，则可以像这样在括号内传递它们:

As always with Perl, "There's More Than One Way to Do It." For example, if any of those subroutines took parameters, you could pass them inside parenthesis like this:

for my $routine_ref (@routines) {
  $routine_ref->();
}

还请注意，我使用的是for而不是foreach，这是 Damian Conway的Perl最佳做法.

Also note that I've used for instead of foreach, which is a best pratice put forth by Damian Conway in Perl Best Practices.

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