perl: Please explain this for me: $hexdigit = (0 .. 9, 'a' .. 'f')[$num & 15];


 
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# 1  
Old 05-21-2009
perl: Please explain this for me: $hexdigit = (0 .. 9, 'a' .. 'f')[$num & 15];

This is taken from perlop. I can't understand what's going on, please can someone explain this for me?

Code:
$hexdigit = (0 .. 9, 'a' .. 'f')[$num & 15];

    to get a hexadecimal digit

# 2  
Old 05-21-2009
( 0 .. 9, 'a' .. 'f' ) is an array with values 0 1 2 3 4 5 6 7 8 9 a b c d e f
Since it is an array you can reference one of the elements of an array with square brackets [ $num & 15 ] - this provides the hex equivalent of numbers from 0 -- 15.
# 3  
Old 05-21-2009
Thanks a lot!
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