So I'm following the book Learning Perl, there's this code with comments in it:
$rocks[0] = 'bedrock';
$rocks[1] = 'slate';
$rocks[2]= 'lava';
$rocks[3] = 'crushed rock';
$rocks[99] = 'schist';
$#rocks = 2; # forget all rocks after 'lava'
$#rocks = 99; # add 97 undef elements (the forgotten rocks are gone fo
+rever)
If I do
print $rocks[$#rocks]; it prints nothing. Why? When I comment out
$#rocks = 99; it prints 'lava' and when I comment out
$#rocks = 2; it prints 'schist'. But when I maintain the two it prints nothing as I already said. And what the comments "add 97 undef elements (the forgotten rocks are gone forever)" and "forget all rocks after 'lava'" mean?