如何使用perl正则表达式从“[1]”中提取数字值？

My code...

$option = "[1]";
if ($option =~ m/^\[\d\]$/) {print "Activated!"; $str=
 
 
My code...
 
 
$option = "[1]";
if ($option =~ m/^\[\d\]$/) {print "Activated!"; $str=$1;}
 
 
I need a way to drop off the square brackets from $option. $str = $1 does not work for some reason. Please advise.
 
 
我需要一种方法从$ option中删除方括号。 $ str = $ 1由于某种原因不起作用。请指教。
 
  
  
 
2 个解决方案
 
 
 
  
#1
 
  
 
  
 
   
6  
 
   
if ($option =~ m/^\[(\d)\]$/) { print "Activated!"; $str=$1; }
 
   
Or
 
   
if (my ($str) = $option =~ m/^\[(\d)\]$/) { print "Activated!" }
 
   
Or
 
   
if (my ($str) = $option =~ /(\d)/) { print "Activated!" }
 
   
..and a bunch of others. You forgot to capture your match with ()'s.
 
   
..和其他一些人。你忘了用()来捕捉你的比赛。
 
   
EDIT:
 
   
if ($option =~ /(?<=^\[)\d(?=\]$)/p && (my $str = ${^MATCH})) { print "Activated!" }
 
   
Or
 
   
my $str;
if ($option =~ /^\[(\d)(?{$str = $^N})\]$/) { print "Activated!" }
 
   
Or
 
   
if ($option =~ /^\[(\d)\]$/ && ($str = $+)) { print "Activated!" }
 
   
For ${^MATCH}, $^N, and $+, perlvar.
 
   
对于$ {^ MATCH},$ ^ N和$ +,perlvar。
 
   
I love these questions : )
 
   
我喜欢这些问题:)
 
  
 
 
 
 
 
  
#2
 
  
 
  
 
   
7  
 
   
To get $1 to work you need to capture the value inside the brackets using parentheses, i.e:
 
   
要获得1美元的工作,您需要使用括号捕获括号内的值,即:
 
   
if ($option =~ m/^\[(\d)\]$/) {print "Activated!"; $str=$1;}
 
  
 
 
 

;}
$option = "[1]";
if ($option =~ m/