Perl Tutorial - 36: Comparison Operators (Numbers) Video Lecture | Perl Building Blocks: An Introduction to Perl - Back-End Programming

hello guys welcome to my channel this is
the 36th tutorial in this course and in
this little we'll be talking about
comparison operators in Perl and we have
been using comparison operators with if
statement and even with loops for
preparing our test conditions but we
haven't formally met them yet and we're
gonna do that in this video so
comparison operators are also known as
relational operators so if someone is
talking to you about relational
operators and just know that you know
the person is talking about operations
like whether the values are equal or if
one value is less than the other and
there are a bunch of other operations
that you can perform using comparison
operators so I have a very simple script
here it's got some cord but it's really
simple so we're going to demonstrate the
operators using if statements and we're
going to check for you know different
tests and on the basis of the output
that we get we're going to display you
know some statements on the output
window so I have a script that's called
comparison underscore operators and risk
or numbers there's going to be a
separate tutorial on strings in which we
see how we can use comparison operators
to compare text values but for the time
being we're going to work with two
scalar variables x and y which have
values 20 and 15 respectively
so the first comparison operator that
we're going to check out is the double
equal to comparison operator and this is
used to check if the two values in the
variables that you're comparing are same
or not so you know you have an if
statement on line number six which is
going to check whether the value in X is
equal to the value in Y or not if it is
then it's going to display the values of
x and y and it's also going to show the
message x and y are equal and obviously
we're not going to see x and y we're
going to see the values that are stored
in X and Y because we have the variable
names enclosed within double quotes so
the values will be interpolated and then
on line number ten if you
check where the values are different not
instead of using two equal to symbols
you would use the exclamation symbol
with one equal to symbol right so this
makes it not equal to and this print
statement would work if the numbers if
the variables had different numbers and
you know in current case since X has 20
and Y has 15 we should actually see 20
and 15 are not equal and then on line
number 14 I have another if statement
that's going to check if the value in X
is less than the value in Y on line
number 18 I have an if statement that's
going to check whether the value in X is
greater than the value in Y and then on
line number 22 I have the less than
equal to comparison operator which is
going to check whether the value in X is
either less than or equal to the value
in Y and then finally on line number 26
I have a new statement that's going to
check if the value in X is greater than
or equal to the value in Y so and make
sure the script is saved and with the
initial values 20 and 15 I'll run it to
see the output so we see 20 and 15 are
not equal and 20 is greater than 15 and
20 is also greater than or equal to 15
right so that's the output that you get
from this if statement the one on line
number 10 and then the asturian on line
number 18 and also the if statement on
line number 26 now let me make this you
know let me change this from 15 I'll
change it to 25 and I'll execute the
script again and we see 20 and 25 or not
equal 20 is less than 25 and 20 is less
than or equal to 25 so this time we are
seeing output from the a statement on
line number 10 this one's still working
and then we are seeing the output from
the external line number 14 as well as
the if statement on line number 22 and
finally let's make the values equal so
I'll change this to 25 so
the if-statement on line number six the
one on line 22 and the one on line 26
all result in to true 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 am
going to see you in the next video till
then take care