Fortran Programming Tutorials (Revised) : 003 : Implicit None + Simple Data types Video Lecture | Introduction to Fortran Programming (Basic Level) - Database Management

hello guys my name is Aaron and welcome
to my channel this series is a series of
tutorials on photon programming and now
you guys are in the third video of the
series now in this video we look we like
will go into a little more detail
frog a little more details of
programming and I'll explain you guys
Saturn sin taxes that are being followed
in Fortran now now I already have code
blocks operate here what I do is just
click this new project file or there's
this option called as new or the option
covers new file what I do is click a new
project click for turn applications over
here or else you can just you know ready
you know filter the options and click
photo application whichever you
whichever you go and let this option be
available click Next and here let's say
I let me just today I'm going to explain
you guys about numbers and implicit none
so let me type the name it has numbers
so it would be the project name will be
numbers dot CBP okay
click Next and then here said this to
you know say this to give no photon
compiler click and next make sure these
optional clicked click finish and there
you have it and now in this tutor in
this session in this video I mean in
this folder this our project we have a
folder called as Fortran source and then
you have a inside having a main dot F 95
click this you have a default program
written let's delete this up okay I like
let's write a comment to stay what we're
doing here program to explain the
numbers okay numbers
and data type types in Fortran okay okay
okay now ask us earlier let's start
writing to start a program you need this
keyword program and then you type your
program name I call it numbers now I end
the program with the keyword n space
program and then I typed numbers to make
sure it make sure this goes well and
then what I do I write this command call
us if we not a common keyword call us
implicit them now I'll explain you guys
what the implicit actually means see in
Fortran 77 and and 3/4 times 66 make the
very oldest versions of Fortran the vs.
rule that the compiler takes by default
what it what did what this rule is
suppose if some variables start with let
us l m n and so on okay
the compiler the count of the compiler
assumes them to be integers by default
and if there are other variables like a
B C X Y Z or Z which are you call it the
compiler assumes them to be real real
numbers or floating numbers by default
now for very simple applications this
meant this might be ok but if you have a
very large number of variables that you
have to process process a lot and and
suppose if you have some variables that
start with the letter L which I need not
which are not necessarily integers at
the same time some variables which start
with letter ABC which are indeed
integers then this this notation will
the will be there will be no minimizing
the number of K variable options will a
variable name
we'll have to make sure that this
problem does not happen and to make sure
the compiler does not throw an error or
something like that okay
implicit none comes into picture now
what implicit nun says is that it says
to the compiler do not assume the data
type of any variable on your own instead
as the user to explicitly expel what the
data type of any variable is so that
being said if I were to create any debt
any variable okay
suppose if I don't have any implicit
none okay if I don't have any implicit
none okay if I just create a if I just
create something like L equals five
something by the l equals Phi will
automatically assume you have to be an
integer and a equals 8.9 you don't have
to write but automatically a will bless
him to be a real number real number or
not now this this may not be good if
it's away if it's a really advanced
program that can eNOS will mix and
matches stuff it's fine but if it's a
simple program then it's not good
instead we have to mention too it's very
clearly so implicit none is important
okay I let these comments over here so
that you guys can access these video
access these files later on and then let
me go to the main part of it there are
different types of there are a few types
of numbers and data types available
Foton the first one is integer integer
okay this will store all positive or
negative values with these numbers are
those wish to not have okay they do not
have a fraction part of it meaning if
you not not know where no numbers are
not the similar points there is complete
whole numbers this can be positive or
negative okay and then if you want to
declare any variable with an integer
what you do is that type integer and
type the variable name like this a b c
and all that's it and
suppose then I suppose if you want to
write a number which hat which has which
has decimal points and all okay what do
you use is that use this comma use a
keyword real real stands for the normal
numbers that we use in the scientific
application which have both the whole
number part and decimal part of it so if
I just so this way if you use this
keyword the variant that we type along
here like AR BR SIA etc these are all
real numbers will be different and there
are two more two more
numbers called us you know sometimes the
photon might accept something called as
double which is actually which is
actually this is basically real number
but it occupies twice the memory then
the tougher real number the reason is
because the reason is because the more
memory you give for numbers especially
real numbers and integers the more will
be the width of the number you can store
no more number to play there is a
significant places you can store and if
you guys want to know more about this go
to V key and type integer integers
definition okay and if you guys go to
Wiki Wikipedia they will give you guys a
big big funny my internet is a little
slow here it will show you guys a very
very big list of what integers me but
this is actually they come
mathematically teacher see click this
integer the computer sense this will
explain you guys clearly as to how
integers are and what are the different
type of different various it can store
and all the ranges of it see the more
bits they're integer store long story
shot the more bits the integer store the
more is the range of the numbers it can
store for instance a 32-bit integer mean
an integer which stores its takes four
bytes of memory okay sobytiya four bytes
of memory can store a number as big as
this let's see this is hundred thousand
million yeah you can store a number as
big as two billion 147 million four
hundred eighty three thousand six
1:48 okay from the negative part to the
positive part of it and suppose if a
number is an integer is like sixty
four-bit or it takes eight bytes of
memory then you can store a number as
bigger says let's me as big as this and
if it's more if it's if it occupies
little more a twice the amount of this
it can 16 bytes if I were to be right or
something if I were to be right it
occupies it can store a number as big as
this okay this is for integers similarly
there is a notation for doubles and real
numbers also I recommend you guys have
look at it and if you want if you want
to declare double numbers what you do is
to just add double and then type yeah
then the variable names like a d VD P D
CD and up okay this R stands for a real
number D stands for double as I just
mentioning here just for you guys to
know and then there is this one word
edited called as complex okay yes
like call AC BC CC and all what these
complex numbers do is that they have you
can use these numbers to store imaginary
numbers like for 4 plus 5i 4 plus 5i 7 -
9 point 3 J something like that if you
have a complex numbers like this and if
you want to use them in some arithmetic
processes and combinations which is
quite likely for them to come the
complex numbers to it members and
there's nothing to worry about case n
type type sensitive here because complex
numbers by default assume the values to
be real or double so it doesn't matter
and finally there are two more values
that that have 2 X to tell you guys here
ok maybe there's one more thing
this one think all's character now okay
let me spell it right yeah character is
b CH c CH and off okay now what I
character does is that it just stores a
single symbol single symbol or a number
or a very ordered alphabet or anything
okay that this what a character stores
and using characters you can make
strings also and we'll go to that acid
when you come with an example I'll
explain you guys how to write strings
and all you see character define strings
or not and there's finally one more
basic data type called us come logical
okay logical data type like these are
used for storing for storing or by
nayfeh story and the manipulating or
working with binary answers suppose if
you have to make addition this or that
or true or false
yes or no or bind if a certain wrestle
operation gives answers like 1 or 0
those kind of stuff logical numbers are
very useful logical numbers are very
logical numbers of various would be and
they can they can store only true answer
to answers either true or false
well that's all I have for this tutorial
my total my aim in the city last
explaining guys about implicit learn and
the types of variables available please
do remember these variables because data
types because we will be using them very
often in the subsequent programs and all
so so Duke you guys do keep an order fit
and we will see examples on how to use
these and use these in the subsequent
subsequent programs that's all I have
for you guys in this tutorial thank you
guys for watching see you guys the next
time