I can see that the value corresponding the key held in the $dir variable in the hash called sub is a reference to another hash and that we are dereferencing it

Doesn't look that way to me. $dir should be a straight scalar variable. Nothing is being dereferenced with that syntax either.

But why is the key CALLBACK in captials and unquoted.

The caps are presumably just style. You can use string literals/barewords unquoted in perl if you run without use strict -- which general consensus at this point is there is no reason to not use strict. It helps. (You will get a warning if you use warnings anyway, about potential future reserved words.) HOWEVER, as per previous posts, hash keys are always okay.

In reply to Re: beginner question - why is hash key unquoted and in capitals by halfcountplus
in thread beginner question - why is hash key unquoted and in capitals by Anonymous Monk

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