Changing the order of elements in the variable

Shaveta_Chawla has asked for the wisdom of the Perl Monks concerning the following question:

$author = "Smith, Kristin A.; Shirley, Mark Harper ; Saff, David ; Ernst, Michael D.; Patrick, Nicholas J. M ; Yu, (Jeffrey) Hu; De La Macorra, F ; Smith, Meghan. ";

this variable has author names , but my target is to change the order of individual author, like "Smith, Kristen A." should change to "Kristen A. Smith".

I have used the following code::

@author = split(';', $author);
$ca = scalar(@author);
for (my $i=0; $i<$ca ; $i++)
{
    ($a, $b) = split(',', $author[$i]);
    $author[$i] = "$b$a";

}
$author = join(',', @author);
print "$author\n";
[download]

i find this code really complex. Please suggest a better code using map function.

Comment on Changing the order of elements in the variable Download Code

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Re: Changing the order of elements in the variable by moritz (Cardinal) on May 30, 2012 at 06:59 UTC
`$author = join '; ', map { join ' ', reverse split /, / } split /; /, $author;` [download] Or as a regex substitution: `$author =~ s/([^,;]+),([^,;]+)/$2 $1/g;` [download] Perl 6 - the future is here, just unevenly distributed	[reply] [d/l] [select]
Re^2: Changing the order of elements in the variable by bimleshsharma (Beadle) on May 30, 2012 at 11:01 UTC
That's fantastic.. But one comma (,) is missed- it seems. `$author =~ s/([^,;]+),([^,;]+)/$2, $1/g;` [download]	[reply] [d/l]
Re^3: Changing the order of elements in the variable by kcott (Archbishop) on May 30, 2012 at 11:30 UTC
You can check this sort of thing on the commandline: usually advisable if you're going to tell someone they got something wrong. Shaveta_Chawla wants: "... "Smith, Kristen A." should change to "Kristen A. Smith".". moritz' solution does this: `$ perl -Mstrict -Mwarnings -E 'my $author = q{Smith, Kristen A.}; $aut +hor =~ s/([^,;]+),([^,;]+)/$2 $1/g; say $author' Kristen A. Smith` [download] Your correction does not do this: `$ perl -Mstrict -Mwarnings -E 'my $author = q{Smith, Kristen A.}; $aut +hor =~ s/([^,;]+),([^,;]+)/$2, $1/g; say $author' Kristen A., Smith` [download] -- Ken	[reply] [d/l] [select]
Re: Changing the order of elements in the variable by choroba (Cardinal) on May 30, 2012 at 07:05 UTC
I am not sure it is any "better". Even a smaller improvement (e.g. using `for (@author) { ... }` instead of the C-style loop can please someone. `#!/usr/bin/perl use warnings; use strict; my $author = 'Smith, Kristin A.; Shirley, Mark Harper ; Saff, David ; +Ernst, Michael D.; Patrick, Nicholas J. M ; van der Loede, Greg; Yu, +(Jeffrey) Hu; De La Macorra, F ; Smith, Meghan. '; $author =~ s/.\s$//; print((join ', ', map { join ' ', reverse split / , /; } split / ; */, $author), '.');` [download]	[reply] [d/l] [select]
Re: Changing the order of elements in the variable by MidLifeXis (Monsignor) on May 30, 2012 at 12:42 UTC
A note on this section of code: `($a, $b) = split(',', $author[$i]);` [download] It is often recommended not to use `$a` and `$b`, as they are special-cased in some functions within perl (sort, for example). You could get some funky results if you collide with one of these cases. "Better" names might be `$lastName` and `$firstNameAndInitial` or `$partBeforeComma` and `$partAfterComma`. You could also trim off the space along with the comma with: `split(',\s+', ...)`, but then you need to also adjust your assignment in the next line. --MidLifeXis	[reply] [d/l] [select]
Re: Changing the order of elements in the variable by uday_sagar (Scribe) on May 30, 2012 at 07:13 UTC
Your had almost reached, but I see that you have got a slight confusion between comma (,) and semicolon (;) These are the slight changes to your code: `line 6, $author\[$i\] = "$b, $a"; line 9, $author = join(';', @author);` [download] Thats it! :-)	[reply] [d/l]