You're unintentionally modifying the hash values before the assignment. True, it's harmless in this case, but I think it's a bad habit. You also have loads of useless options on your substitution. 
%hash = map { my $s=$_; $s=~s/\s+//g; $s } %hash;

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or 

use List::MoreUtils qw( apply );
%hash = apply { s/\s+//g } %hash;

[download]

In reply to Re^2: Strip spaces in hash by ikegami
in thread Strip spaces in hash by kalyanrajsista

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