匹配正则表达式并在单行代码中分配结果 [英] Match regex and assign results in single line of code

问题描述

我希望能够对变量进行正则表达式匹配并将结果分配给变量本身.最好的方法是什么?

I want to be able to do a regex match on a variable and assign the results to the variable itself. What is the best way to do it?

我想在一行代码中基本上合并第 2 行和第 3 行:

I want to essentially combine lines 2 and 3 in a single line of code:

$variable = "some string";
$variable =~ /(find something).*/;
$variable = $1;

有没有更短/更简单的方法来做到这一点?我错过了什么吗?

Is there a shorter/simpler way to do this? Am I missing something?

推荐答案

你为什么希望它更短?真的重要吗?

Why do you want it to be shorter? Does is really matter?

$variable = $1 if $variable =~ /(find something).*/;

如果你担心变量名或者重复做这个，把东西包在一个子程序里，不管它:

If you are worried about the variable name or doing this repeatedly, wrap the thing in a subroutine and forget about it:

 some_sub( $variable, qr/pattern/ );
 sub some_sub { $_[0] = $1 if eval { $_[0] =~ m/$_[1]/ }; $1 };

无论您如何实现它，子例程的重点是使其可重用，因此您可以为一组特定的行指定一个简短的名称来代替它们.

However you implement it, the point of the subroutine is to make it reuseable so you give a particular set of lines a short name that stands in their place.

其他几个答案提到了破坏性替代:

Several other answers mention a destructive substitution:

( my $new = $variable ) =~ s/pattern/replacement/;

我倾向于保留原始数据，并且 Perl v5.14 有一个 /r 标志，它不影响原始文件并返回一个带有替换的新字符串(而不是替换的计数)):

I tend to keep the original data around, and Perl v5.14 has an /r flag that leaves the original alone and returns a new string with the replacement (instead of the count of replacements):

my $match = $variable =~ s/pattern/replacement/r;

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