perl sort   <=> and cmp

Perlhas two operators <=> andcmp,

which are veryuseful when wishing to sort arrays. $a<=> $b returns -1 if $ais numerically lesser than $b, 1 if it's greater, and zeroif they are equal.

cmp does the same for string comparison.For instance the previous example could be re-writtenas:

[liuguiyou@localhost perl]$ cat sort.pl
#!/usr/bin/perl
 
use strict;
use warnings;
 
my @array = (100,5,8,92,-7,34,29,58,8,10,24);
 
my @sorted_array = sort { $a <=> $b } @array;
 
print join("<", @sorted_array), "\n";
 
[liuguiyou@localhost perl]$ ./sort.pl
-7<5<8<8<10<24<29<34<58<92<100
 
  

Muchmore civil, isn't it? The following example, sorts an array ofstrings in reverse:

[liuguiyou@localhost perl]$ cat sort_chara.pl
#!/usr/bin/perl
 
use strict;
use warnings;
 
my @input = (
    "Hello World!",
    "You is all I need.",
    "To be or not to be",
    "There's more than one way to do it.",
    "Absolutely Fabulous",
    "Ci vis pacem, para belum",
    "Give me liberty or give me death.",
    "Linux - Because software problems should not cost money",
);
 
# Do a case-insensitive sort
my @sorted = sort { lc($a) cmp lc($b); } @input;
 
print join("\n", @sorted), "\n";
 
 
[liuguiyou@localhost perl]$ ./sort_chara.pl
Absolutely Fabulous
Ci vis pacem, para belum
Give me liberty or give me death.
Hello World!
Linux - Because software problems should not cost money
There's more than one way to do it.
To be or not to be
You is all I need.