Perl Tutorial - 44: Subroutines Video Lecture | Perl Building Blocks: An Introduction to Perl - Back-End Programming

hello guys welcome to my channel this is
the 44th tutorial in this course and in
this role we'll be talking about
subroutines and Perl so a subroutine is
a function you could call it a method
and if you've programmed in other
languages then you would know the
advantages of using functions and if you
haven't well it's it's really quite
simple to understand why you would want
to use functions if there is something
that you would want to do over and over
again in your script
it could be adding two numbers or
concatenating first-name and lastname
and creating full name or you know doing
simple earth medic or performing some
operations on strings if there is
something that you are doing over and
over again then instead of writing that
piece of code you know as many times as
you need you could just create a
function and then call that function
whenever you need it
so in perl we call functions subroutines
and there really is no other difference
between functions in other languages and
subroutines in Perl the syntax is
slightly different maybe but in terms of
execution and the way you interpret the
concept of functions Paul is is is you
know the same as other languages so I've
got a script here that's called
subroutines and in this script on line
number 3 I have used the keyword
sub and this is the keyword that you use
to create a function in Perl and after
typing in sub you have to give space and
then you have to mention a name for your
function so I'm going to call my
subroutine message and then there's a
set of empty parentheses and then
between the curly opening curly brace on
line number 4 and the closing curly
brace on line number 6 I have one print
statement on line number 5 and this is
all the code that this subroutine
contains and you don't just have to put
one line here even if you have like 1500
lines between the opening and closing
curly brace it's fine there is no
restriction on the amount of code a
subroutine can hold by
the this subroutine is is a very simple
subroutine it's just going to display
the message hello youtubers so that's
why I have a print statement here which
is going to display hello youtubers with
an exclamation symbol and just creating
the subroutine is not going to serve our
purpose because we want to see this
output so we don't just have to create
this but you also have to call it or we
want this code to execute so you call a
subroutine by just typing its name and
if you put a pair of empty parentheses
after the subroutine name then you would
have to put that here as well and in the
next tutorial we are going to talk about
how you can pass arguments to
subroutines in Perl and for the time
being there is no argument that the
subroutine is going to accept and hence
you have the empty parentheses here and
of course since this is an executable
statement you would have to terminate it
with a semicolon
and that says it's it's ready we can
execute the script by pressing f5 and
there we go when I press f5 I see the
message hello youtubers with exclamation
so that's it about subroutines I hope
you guys had fun watching this video you
may subscribe to my channel if you
haven't already I'm going to see you in
the next tutorial then take care