11 Sample FORTRAN Programs by 27-150 Student[name lost]
```C Program #1
C This program prints words to the screen

print *,'Hello World'
end
```

```C Program #2
C This program inputs a number and then prints it

C First declare the variable, the thing you are going to input
integer number

C now input the number from the keyboard
print *,'Enter an integer'

C now print the number that was inputed
print *,'The number you typed was...'
print *,number
end

```

```C Program #3
C This program inputs a name and then prints it

C First declare the name as a character
character*20 name

C Now get the input from the keyboard
41      format (a20)

end

```

```C Program #4
C This program inputs a variable and then assigns that number to
C a new variable and then prints the result.

C First declare the two variables
integer var1, var2

C now input the number from the keyboard
print *,'enter an integer'

var2 = var 1

print*,'Now printing the value of var2:',var2
end

```

```C Program #5
C This program takes you number and adds to it several times

C First declare the variable
integer i

C Input the variable
print*,'Enter an integer'
print*,'Here is i',i
i = i + 1
print *,'Here is the new i',i
i = i + 1
print *,'Here is the next i',i
i = i + 1
print *,'And here is the final i',i
end

```

```C Program #6
C This program shows simple if structure

C First declerations
integer number

C Now input the value
print *,'Enter an integer'

if (number.eq.1) then
print *,' you picked the number one'
endif
end

C Note that with the indent it is easier to read
C but this extra indent makes the program easier to read

```

```C Program #7
C THis program shows more complicated if structure

C First declare the variable
integer number

C Then input a number
print *,'Enter an integer'

if (number.eq.1) then
print*,'That was the number one'
elseif (number.gt.7) then
print*,'Greater than 7'
elseif (number.le.-4) then
print *,'less than or equal to -4'
else
print *,'I don''t know what to do'
endif
end

```

```C Program #7
C THis program shows more complicated if structure

C First declare the variable
integer number

C Then input a number
print *,'Enter an integer'

if (number.eq.1) then
print*,'That was the number one'
elseif (number.gt.7) then
print*,'Greater than 7'
elseif (number.le.-4) then
print *,'less than or equal to -4'
else
print *,'I don''t know what to do'
endif
end

```

```C program #8
C This program demonstates a while loop

C declerations
integer number, i
C something new, set a value to one of the numbers
i = 1

C main
print *,'Enter an integer, less than -100 to exit'

while (number.gt.-100) do
print*,'THis is in a while loop'
print*,i
i = i + 1
print *,'enter an integer, less than -100 to exit'
endwhile
print *,'Now you are out of the while loop.'
end
```

```C program #9
C This program demonstrates a do loop (right out of lab 1)

C declerations
integer a

C main
do 10 a = 0,50,5
print *,a
10      continue
end

```

```C program #10
C this program demonstrates a do loop with variables

C declerations
integer loop, start, ending
start = 5
ending = 16

C main
do 53, loop = start,(ending-1)
print*, loop
53      continue
end

```

```C program #11
C this program contains an array

C declerations
integer array(5)

C main
C first input numbers into the array
do 67 i = 1,5
print*,'Enter array element #',i
67      continue

C now all the information is in the array, we can look at
C elements individually like this

print *,'----------------------------------------'
print *,'The 4th element is',array(4)
print *,'The first element is',array(1)
print *,'----------------------------------------'

C We can also print everything up in a loop

do 34 i = 1,5
print *,'Here is array element',i
print *,array(i)
34      continue
end

```