Update: Bah, I should head my own advice. The second statement never gets a chance to execute.

You're looking at the statements in isolation. Look at them as a pair.

Original post: (WRONG!) 

# First time
next unless defined %{$matches{$fasta_id}};         # False
last unless defined @{$matches{$fasta_id}{$site}};  # False

# Second time
next unless defined %{$matches{$fasta_id}};         # Now true!!
last unless defined @{$matches{$fasta_id}{$site}};

[download]

What really happens: 

# First time
next unless defined %{$matches{$fasta_id}};         # False -> next
last unless defined @{$matches{$fasta_id}{$site}};  # Skipped by next

# Second time
next unless defined %{$matches{$fasta_id}};         # Still false
last unless defined @{$matches{$fasta_id}{$site}};

[download]

In reply to Re^3: Help tightening up a subroutine please by ikegami
in thread Help tightening up a subroutine please by mdunnbass

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