Perl Tutorial - 14: Slicing Hashes Video Lecture | Perl Building Blocks: An Introduction to Perl - Back-End Programming

hello guys welcome to my channel this is
the 14th tutorial in this course and in
this tutorial we're gonna see how we can
slice hashes and obtain values from
hashes in Perl so I've got a script
opened up here it's called hashes
underscore slice and in this script on
line number 3 I have created a hash
called players I've used the percent
symbol to create the hash and this is
similar to the players has that we
worked with in the last tutorial it's
just that I've added another key value
pair for Kei Nishikori so this one has
four key value pairs Rank 1 belongs to
Novak Djokovic and then at number 2 we
have Roger
number 3 is Andy and number 4 is case so
you know this was the rankings at the
time of you know making the script now
the rankings have changed andy murray is
the number two player in the world Roger
Federer is at number three and I guess
if I'm not wrong Stanislas Wawrinka at
number four and Nishikori is maybe at
six
so anyway coming back to the topic of
slicing hashes so let's say you want to
fetch a bunch of values from this hash
you know not just one so if you were to
fat just one value then you could do it
the way I demonstrated in the last
tutorial by you know creating a
temporary scalar reference by using the
dollar symbol and then you know just
typing the key within curly braces but
here let's say you want to you know
fetch all values you know all four names
novak roger
andy n k then the way you do that is by
creating an array variable because if
you were fetching multiple values in a
single statement then you would get the
values in a list and the data structure
in perl that is designed to work with
this is the array data structure so you
would have to create or you know store
the output in an array so i have done
that on line number five i have created
an array variable called my underscore
list i put the equal to symbol and then
since we are fetching values
in lists phone we have to use the add
the rate symbol here you know for
slicing this hash so if you were
fetching one value then you use a dollar
symbol with the hash name but here since
we are fetching multiple values we have
to use the add the rate symbol because
as I said we're going to get the output
in list form so players is the name of
the hash you put the address symbol
first and then within curly braces you
just type in your keys and you could
either type 1 comma 2 comma 3 comma 4
here if you wanted all four values or
you could just put two dots between 1
and 4 and pearl would sort of
autocomplete and you know get you the
other two keys in between so this is
going to do the job for us the next
thing that we have to do is to display
the values that we fetched so that we're
going to do that using the print
statement on line number 7 top tennis
players in the world and we're just
going to output the contents of the
array variable my list which we have
just created right so I'll make sure the
script is saved I'll press f5 to run it
so there we go in the output we see top
tennis players in the world Novak Roger
and Ian K we see all four values and if
instead of the two dots said if I would
put a comma then we should only see
Novak and Kay's name because we are
selecting values for only two keys one
and four and I'll run the script and
there we go we only see Novak and K so
that's it for this tutorial I hope you
guys had fun watching this one and you
may subscribe to my channel if you
haven't already I'm going to see you in
the next video till then take care