Re: Reversing string case

[nvivek]

Following code will help you.

use strict;
use warnings;

print "Enter the string:";
my $string=<STDIN>; #getting the input from user
 
chomp($string); #remove the newline at end in string

if($string=~/^[a-z]+$/) { #checking whether the string is in lowercase
print "String given in Lower Case:$string\n";
$string=~s/([a-z])/\u$1/g; #replacing the string to be in upper case
print "Uppercase String:$string\n";
}
elsif($string=~/^[A-Z]+$/) { #checking whether the string is in upperc
+ase
print "String given  in Upper Case:$string\n";
$string=~s/([A-Z])/\l$1/g; #replacing the string to be in lower case
print "Lowercase String:$string\n";
}
elsif($string=~/^[a-zA-Z]+$/) { #checking whether the string is in mix
+ed case
print "String given in Mixed Case:$string\n";
$string=~s/([a-z])/\u$1/g; #replacing the string to be in upper case
print "Uppercase String:$string\n";
$string=~s/([A-Z])/\l$1/g; #replacing the string to be in lower case
print "Lowercase String:$string\n";
}

[Anonymous Monk]

Your mixed case test will not work the way you intended

/[a-zA-Z]/ matches any lower- or uppercase character, not a lower- and then an uppercase one.

And your two substitutions will not flip the case of a character because after the first substitution (i.e. s/([a-z])/\u$1/g) all characters are uppercase and will be changed to lowercase at the second substitution.