Fortran Programming Tutorials (Revised) : 029 : Cycle; Exit; More on Do loop 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 now in
the last few lectures we saw a lot of
concepts and topics regarding formatting
and other examples of doing some
programs and this is little in this
lecture and video we will see you some
will see one negative one feature of do
loop that we didn't cover in the past in
this loop we in this program will be
working and looking at examples of
working examples of how to use a do loop
without a counter variable now in the
last the the previous examples on the
last few examples you might have seen
that a do loop requires a counter
variable in this example we will see how
to make a do loop run without a counter
variable now what I have here is a small
program called a sum underscore digits
dot F 95 okay
the this is a file in the program may be
some underscore digit it starts here and
ends here what this program does as
mention the comment it has two parts one
it does it finds the number sum of the
digits of a positive integer number and
then it continuously ask the user to
user together and input a certain number
of positive digits positive numbers in a
series of entries and I will count the
number of positive entries you put in if
I want to compile this builders and
execute this let me see how other
initially it can it finds is fine so
some of the positive digits I mean some
of the power some of the deter of a
positive number so I guess our number
like 1 4 by 2 so the sum of the digits
is 9 to 11 plus 1 12 so it should find
so this program calculates the sum and
the temporary value value of a
temperature but these in every instant
and then finally gives the number the
number is 1 1 the number is 1 for Phi 2
and the sum of the digits is 112 now you
have to now what you have to do is that
we have to enter a value from now you
have to enter a value from 1 to n ok now
it's a mess initially occupy sorry I
just made in the end here but it doesn't
matter let me just give early like hi
now enter 10 okay so this again should
be five the second should be Phi anyway
let me give the value Phi minus nine
four five again nine again to again it
shows that now the prints that I have
entered for positive numbers of the five
chances okay this is how the program
works
now let me you know make let me you know
the walk you guys through okay we have a
program named assam underscore digits we
have the implicit none and we have five
variables in the first three variables
in the first line now someone temp okay
and here three variables in county pulse
one and on the integer i count equals
count one equals zero and i now in this
line we mentioned to the reader we
mentioned to the user that we we are
asking for a positive integer and we are
reading that value through this variable
now what I'm doing is that I'm saving
this number inside the temp insider term
enter a variable called a stamp this
term will be under magnification and I'm
initializing some the variable some one
equals zero now I have a do loop in
which this do loop if it does not have a
counter variable like I so this do loop
starts here and ends here now let's see
what happens inside I gave an if
statement stating that if this temporary
variable becomes zero then exit now what
this this line mean it means that
whenever you get a temporary variable 0
okay this entire if statement and this
looping statement will terminate and it
will come out on the other hand another
hand if the temporary variable is not
equal to 0 then the else statement of
the if then else part of the Zips if
then else statement starts now what
happens here is that initially sum is 0
and what happens is that this sum gets
added with the modulus operator modulus
operation of the stem two variables it
done now if we divided now if we divide
a number by 10 divide a number by 10
will give ur it will give us a
give us a reminder reminder and that
reminder will actually be the last digit
if you remind if you divide a positive
integer by 10 it will give us a last
digit okay so and this someone will be
the sum of all the last digits of the
number from the from the back now what
does 10 temp variable does is that it
takes the advant it it gets stored with
the actual value of term they were about
10 now since tempest an integer tempest
an integer the truncate the this value
here will truncate the la will truncate
the digits
well truncate the decimal parts and we
just store only the remaining part so
suppose if we enter a lot numbers say
hundred hundred and twenty-four here
this will store for okay and temp will
instead became thousand sorry you missed
if a given number like 120 for the
Valley store 4 will be stored here and
in this process the number 124 will
become 12 okay and that some initial
some value on the temp temporary value
after the modification will be printed
here as simple as that now this loop
continues till temp becomes 0 when will
turn become 0 it's when the last digit
gets divided by 10 if you have a single
digit value and if we divide that by 10
that will all ultimately give a fraction
which is less than 1 so it will be
terminated in term becomes 0 and when
that comes this progress the this if
statement becomes true and then this
exits when this exits the entire do loop
is executed it is terminated and finally
and after that that's the first part and
what do you do is it we just print the
value of sum here ok we print the number
and there's some other business in this
sum and variable here and what we do
here is that ok I should have typed this
n but that's ok and and then yeah this
should be right this should be fine ok
now what I do here is that I ask for the
user to enter a number between 1 and 10
and this value should be an integer and
I guess get its tour from the worm into
the variable n okay now what I do is I
printer you tell the user to enter n
values or
positive and negative ever n n+ an
integer I think I don't need these
values okay
enter n positive and negative integers
okay
now that will get now as and when this
happens this loop the loop begins this
do loop begins and in this do loop
unlike the previous one this starts with
the key this starts with an
initialization variable sorry an
incrementing or a right rating variable
I okay and in this loop what I says that
I just you write the print statement it
says enter the I enter the variable I
with a colon meaning every time this
loop runs it will ask for the first it
lasts for the first variable then then
second variables are available so on
depending on the iteration and then what
I do is using this read command I read
the value read the value and here here
comes the interesting part see suppose
if this in temporary variable becomes
less less than 0 indicating the values
negative okay then what this side this
cycle command gets activated know the
cycle key will get saturated
what is this cycle key what does is that
it will not allow the remaining part of
the program to be executed rather it
goes to the first and I tray goes to the
first and restarts the do loop with an
increment in I so it's like whenever you
put that word cycle what does it does
and when that condition occurs whatever
that is written below it yes completely
remove off a completely ignored and goes
back to the beginning of the loop in
this for loop K in this case it because
of the back drag to the beginning of the
follow-up case okay and then well
suppose if you do not enter a past
if you enter a positive number then this
count variable which is initially
counter initialize to 0 gets incremented
by 1 and this goes on till the end I
iterations and then finally the value
print statement prints here it says that
you have entered count two and positive
numbers out of n chances so if suppose
you feel like we have to like for enter
for positive numbers for positive
numbers out of 5 it will show that you
have entered 5 for positive numbers out
of four in five chances now to compile
this
to compile this okay let me open the
terminal okay now we just click L let me
just clear this up clear the screen up
okay if you just press it if I just
press LS I have this Sam underscore
digits and all let me just remove this
up okay okay sorry okay you know I run
this now I can I can compile this on
others in a single line default plan
sums - or flag and then right let's say
digits not exe click enter if everything
works fine it should it should display
it should give us an executive for now
if I just run this this is done exe and
I click it then this ask me for a
positive number let me give a value like
seven eight zero zero so this should
give us some summation of 15 and it runs
and finally this shows the number of
stars this 7800 okay
I knew you guys can notice that the
template variable like because of the
modulus division sorry because integer
division he just removes one decimal
place at a time one decimal place at a
time and then some other digits is 15 as
per as per the I mean and it's great
okay now I have to enter a number
between 1 to 10 let me enter the value
say 5 okay now it asked me to print 5
positive or negative values together
let me with gave like 7 8 minus 4 minus
3 and then 2 okay now it shows you have
entered 3 positive numbers or the 5
chances and the distro 7 is positive 8
is positive 2 is positive whereas minus
4 and minus 3 and negative so what we
did is perfectly right okay now this is
how this is how you work with cycle and
cycle and exit statements and also how
to work with a do loop without having a
counter variable
without having a counter variable now
these if you want to work get these done
get this cycle and exist it was to work
then you definitely need an if statement
and that is kind of necessary and man
necessary and mandatory and now other
than this other other than this there
are there are mother other uses for
cycle and cycle and they exit you I mean
depending on application you might have
to use them really differently but this
is how a basic thing works they I mean
it this might be useful in finding it
finding error values or something of
that you know this might be useful in
finding some error values or you know
missing some problem some problematic
entries and something this might be this
might be useful to know terminate some
program in a row and not not so required
not so require keep key combinations
press or something of that sort
okay that depends on your app that
depends on application well that's all I
that's all I have for you guys in this
tutorial and that thank you guys for
watching and see you guys in the next
tutorial bye