You can answer these questions by running the code yourself, under the perl built-in debugger.

Just run you rprogam like this:

perl -d <Your-program-file-name>
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Inside the debugger prompt , use the "h" (help) command , using "x" check the values of the variables.

Note: You need to FIRST use the "s" command to get the $rec variable initialized.

Here are the results of running your program - it includes answers to your questions:

  DB<1> s
main::(junk.pl:10):     print $rec->{TEXT},"\n",
main::(junk.pl:11):        $rec->{SEQUENCE}[0],"\n",
main::(junk.pl:12):      $rec->{LOOKUP}{"dog"},"\n";
  DB<1> x  $rec -> [Buick]
Not an ARRAY reference at (eval 7)[/usr/lib/perl5/5.10.0/perl5db.pl:63
+8] line 2.
  DB<2> x  $rec -> {LOOKUP} -> {cars}
0  'Buick'
  DB<3> x  $rec -> {LOOKUP} [0]
Not an ARRAY reference at (eval 9)[/usr/lib/perl5/5.10.0/perl5db.pl:63
+8] line 2.
  DB<4> x  $rec -> {LOOKUP} {dog}
0  'hound'
  DB<5> q
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