Perl Tutorial - 21: Elseif Statement in Perl Video Lecture | Perl Building Blocks: An Introduction to Perl - Back-End Programming

hello guys welcome to my channel this is
the twenty first tutorial in this course
and this tutorial we're going to talk
about the elsif statement in Perl
so we've checked out the if statement
we've also checked out the if else
construct but the problem with the if
statement in Perl inside in Perl or in
any programming language for that matter
is that it allows you to make a decision
you know that involves one choice right
or maybe two choices you want to do
something or you don't wanna do
something with else you can selectively
program for the second option you know
so if something is true then you do one
thing and if that thing is false then
you can do another thing so you know
that is what if and else can do for you
but let's say you want to choose from a
bunch of options and that is what this
script is about I have created a file
called elsif and in this script we have
created a Phi function calculator so you
know this calculator will allow you to
add two integers multiply subtract
divide and also find the remainder you
know when you divide one by another so
you know it's a very simple script and
you know let's just go through it so on
line number three I have created a
scalar variable called opie which is
going to store the operator you know
that what the operation that you that we
want to perform on these two numbers X
and Y which I have created on lines 4
and 5 respectively X has the value 20
and Y has the value 10 so we're going to
start with an if statement which I have
on line number seven and to compare
string values in Perl you know you use
the EQ operator and we're gonna talk
about this in more detail later on for
the time being just note that you know
this is a condition and this allows you
to compare the string that's stored in
the variable opie and you know the
operation that you want to perform so if
whatever value is then this is add then
it's going to add x and y store that
result in our yes and then I have a
print statement in the block that's
going to display the result now if the
value in opie is not add
but it's subtract then we wanted to
something else and for that we have the
elsif statement remember if this was
going to be a two function calculator
then I could have just put an else here
but since you know there are lot of
other options that I want to provide I
have to use else--if and the way this is
different from else is that it allows
you to put a condition you know so it it
is basically a combination of the if
statement and the else statement so you
write L safe and then within parenthesis
you type the condition equal sub and
then it subtracts the numbers stores the
result in dollar re s and then it prints
it and similarly I have a code for
multiplied divided and the remainder
operation and remember for the remainder
operation we have to use the percent
operator and then finally I have an else
statement which is going to display
unknown operator in case the value in
Opie is none of these it's neither odd
nor sub multiply divide remainder
whatever right so when I run the file
the way it is right now I see the
message unknown operator because Opie
has an empty string at the moment but
let me change this to add and save the
file and run the program again I see
that the result is 30 because 20 plus 9
is 30 and let me play with one more
value let me change this to multiply and
when I run it I see that the result is
200 and what actually let me also put
REM and when I run the file I see that
the result is zero because 20 is
perfectly divisible by 10 so that's it
for this tutorial I hope you guys had
fun watching this one you may subscribe
to my channel if you haven't already I'm
gonna see you in the next tutorial till
then take care