Fortran Programming Tutorials (Revised) : 006 : Fortran Operators and Operator Precedence Video Lecture | Introduction to Fortran Programming (Basic Level) - Database Management

hi guys my name is Anna welcome to my
channel this series is here tutorials on
photo op rigueur me now in the last
tutorial we saw we wrote a program to
find the area for triangle using neurons
form Heron's formula or Heron's formula
and then we and if you guys noticed this
the same program we wrote last time X
now we will make some slight
modifications to this program ok now
some of the modifications okay before we
make some modifications I gotta explain
you guys give giving your introduction
to you guys as to what these operations
are and okay how addition subtraction
multiplication division power square
root and other operations are being done
Fortran ok so what I do is just know few
leave a few end spaces and start some
comments the addition operation the
symbols plus minus multiplication table
like Asterix and slash they stand for
addition subtraction multiplication and
division are accordingly so we call it a
SMD in shot so a plus stands for add ok
plus stands for add ok - stands for
subtract - stands for subtract
ok the asterisk stands for multiply ok
and then the slash symbol stands for
divide ok now if you guys noticed
noticed as mentioned here ok double
asterisks did not exponent or x4 meant
or power ok ok exponent how you wrote it
spinner for instance if you want to
write something like 2 power 3 which is
equal to 8
ok in Fortran this caret symbol is not
available so this is equal to 2 power 3
so this is the just a equivalent
representation of it and if you guys
want to do a modulus division where and
you guys want to do a modulus division
where in there you want to get the
remainder of it they might have a number
this mod function is available so if
it's like five comma three this will
result in two because this this will
give the remainder modulus function
gives a reminder of the division okay
now this will work for both real and
integer numbers
okay now the before this is this is all
I have for you guys regarding operations
the basic mathematical operations but
then before we go on there is something
you have to keep in mind that is called
as operator precedence
okay okay now what this means is that
when two operations are simultaneously
acting on acting on variables there's an
order in which the variables do for
instance suppose I have like a minus B
into C plus G power raised to the power
Phi something like that can you tell me
which operation happens first which
operation happens second under it's now
some guys might tell me that you know G
will be raised to the power Phi and then
B and C will be multiplied separately
and then and then they get added and
subtracted accordingly some guys might
say that a and B will get subtracted and
then the result will be much the result
will be capacitors while G G C and G
will be added and the power might be
raised to Phi and that answer and this
answer will be multiple and all who is
right both anybody can be right but
thing is that what operator precedence
does is that it just avoids the multiple
I represent a multiple representations
of a so a single expression like this
what it does is that it
operator precedence is that it tells
that which it tells which operated to
happen first which operated up and
second and which operate to happen third
and all okay
now the operator precedence okay is
given by this short name call us PEMDAS
okay meaning paranthesis okay I think
it's para okay it's parenthesis then
exponent exponent multiply or
multiplication multiplication division
addition and then finally subtraction
okay if you want the guys to do if you
guys want to remember this easily there
is this nice little accurate nice little
little mnemonic they used they use call
us please excuse my dear Aunt Sally okay
you guys notice carefully the first
letter of each and every sentence
represents the shot represent the
acronym PEMDAS over here okay this is
something you have to keep in mind and
now with this being said let's look at
this X evaluated over here if you guys
know if you guys to have a look at this
a little carefully little carefully you
don't know exactly which should happen
because of the parent because of the
parent this is being put we will get an
idea of what's going to happen first
initially whatever that will be
available inside this parent this
happens because it follows a PEMDAS rule
and this parent this is the outermost
word so whatever that's inside follows
first so inside what you have is that
you have s times s minus a times s minus
B times s minus C but these values s
minus a s minus B and s minus C since
these are inside enclose within prior
paranthesis these valleys get done
separately so why do you have what do
you have is that s minus a will do first
and then s minus here we'll be doing
done second and s minus C will be done
third and they will be separately I mean
the independently doing done and certain
memory location and then the product of
these four numbers happens next and then
the entire value of this product is it
will be raised to the power point five
so this is actually called as operator
and operator present operator and
operator precedence okay I don't want to
we don't want to know
flash you guys it's a large large amount
of information in one video in the next
video we look at okay we look at you
know how to retrieve how to get these
values from the user and how to you know
how to get these very simple user and so
that we can change the values and
experiment of Rogers and all to see how
the results turn out to be that's all I
have for you guys in this tutorial thank
you guys for watching and see you guys
in the next video bye guys