如何有选择地访问 Perl 子例程返回的元素? [英] How can I selectively access elements returned by a Perl subroutine?

问题描述

假设一个 Perl 子程序返回一个数组:

Say a Perl subroutine returns an array:

sub arrayoutput
{
    ...some code...
    return @somearray;
}

我只想从中访问一个特定的数组元素，比如第一个.所以我可以这样做:

I want to access only a specific array element from this, say the first. So I could do:

@temparray=arrayoutput(argument);

然后参考$temparray[0].

但是这种简短的引用不起作用:$arrayoutput(some argument)[0].

But this sort of short reference doesn't work: $arrayoutput(some argument)[0].

我习惯了 Python 和 Perl 新手，所以我仍在寻找一些简短、直观、类似 Python 的方式(a=arrayoutput(some argument)[0])来获得这个值.我的 Perl 程序变得很长，使用这样的临时数组看起来很丑陋.Perl 有没有办法做到这一点?

I am used to Python and new to Perl, so I'm still looking for some short, intuitive, python-like way (a=arrayoutput(some argument)[0]) to get this value. My Perl programs are getting very long and using temporary arrays like that seems ugly. Is there a way in Perl to do this?

推荐答案

Slices

use warnings;
use strict;

sub foo {
    return 'a' .. 'z'
}

my $y = (foo())[3];
print "$y\n";

__END__

d

或者，您不需要中间变量:

Alternately, you do not need an intermediate variable:

use warnings;
use strict;

sub foo {
    return 'a' .. 'z'
}

print( (foo())[7], "\n" );

if ( (foo())[7] eq 'h') {
    print "I got an h\n";
}

__END__

h
I got an h

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