Re^2: Using regex in Map function

************** Bad Program ****

my @in = qw(a b c d e f g h);

print "Start: ",@in,"\n","***RUNNING MAP***\n\n";
my @out = map { s/.$/x/}  @in;
print "in : ",@in,"\n";
print "out: ",@out,"\n"
[download]

************* Output ******

Start: abcdefgh
***RUNNING MAP***

in : xxxxxxxx
out: 11111111
[download]

*********************
Comment #1:
Use "r" feature on regex
************** fixed Program ****

my @in = qw(a b c d e f g h);

print "Start: ",@in,"\n","***RUNNING MAP***\n\n";
my @out = map { s/.$/x/r}  @in;
print "in : ",@in,"\n";
print "out: ",@out,"\n"
[download]

************* Output ******

Start: abcdefgh
***RUNNING MAP***

in : abcdefgh
out: xxxxxxxx
[download]

****************
Comment #2

But what if you REALLY wanted the return value of the regex - and not modify the original output? (why? I don't know)
Localize the input...

************** fixed Program ****

my @in = qw(a b c d e f g h);

print "Start: ",@in,"\n","***RUNNING MAP***\n\n";
my @out = map { s/.$/x/}  my @temp = @in;
print "in : ",@in,"\n";
print "out: ",@out,"\n"
[download]

************* Output ******

Start: abcdefgh
***RUNNING MAP***

in : abcdefgh
out: 11111111
[download]

Comment on Re^2: Using regex in Map function Select or Download Code

Replies are listed 'Best First'.
Re^3: Using regex in Map function by merlyn (Sage) on Feb 08, 2013 at 18:40 UTC
You're replying to my note from 2007 with a feature that has only been available for a few releases. Nice. -- Randal L. Schwartz, Perl hacker The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119.	[reply]
Re^4: Using regex in Map function by Anonymous Monk on Jan 29, 2016 at 21:12 UTC
However, I found the suggestion of using the /r modifier very helpful in 2016!	[reply]


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