Programming Fundamentals/Conditions/Fortran
conditions.f90 edit
! This program asks the user to select Fahrenheit or Celsius conversion
! and input a given temperature. Then the program converts the given
! temperature and displays the result.
! References:
! https://www.tutorialspoint.com/fortran
! https://en.wikibooks.org/wiki/Fortran
program conditions
character :: get_choice
real :: get_temperature, calculate_celsius, calculate_fahrenheit
character :: choice
real :: fahrenheit, celsius
choice = get_choice()
! if-else approach
if (choice == "C" .or. choice == "c") then
temperature = get_temperature("Fahrenheit")
result = calculate_celsius(temperature)
call display_result(temperature, "Fahrenheit", result, "Celsius")
else if (choice == "F" .or. choice == "f") then
temperature = get_temperature("Celsius")
result = calculate_fahrenheit(temperature)
call display_result(temperature, "Celsius", result, "Fahrenheit")
else
print ("(a)"), "You must enter C to convert to Celsius or F to convert to Fahrenheit."
end if
! select-case approach
select case (choice)
case ("C", "c")
temperature = get_temperature("Fahrenheit")
result = calculate_celsius(temperature)
call display_result(temperature, "Fahrenheit", result, "Celsius")
case ("F", "f")
temperature = get_temperature("Celsius")
result = calculate_fahrenheit(temperature)
call display_result(temperature, "Celsius", result, "Fahrenheit")
case default
print *, "You must enter C to convert to Celsius or F to convert to Fahrenheit."
end select
end program
function get_choice() result (choice)
character :: choice
print ("(a)"), "Enter C to convert to Celsius or F to convert to Fahrenheit:"
read *, choice
end function
function get_temperature(label) result (temperature)
character(*) :: label
real :: temperature
print ("(a a a)"), "Enter ", label, " temperature:"
read *, temperature
end function
function calculate_celsius(fahrenheit) result (celsius)
real :: fahrenheit, celsius
celsius = (fahrenheit - 32) * 5 / 9
end function
function calculate_fahrenheit(celsius) result (fahrenheit)
real :: celsius, fahrenheit
fahrenheit = celsius * 9 / 5 + 32
end function
subroutine display_result(temperature, from_label, result, to_label)
real :: fahrenheit, celsius
character(*) :: from_label, to_label
print ("(f5.1 a a a f5.1 a a)"), temperature, "° ", from_label, &
" is ", result, "° ", to_label
end subroutine
Try It edit
Copy and paste the code above into one of the following free online development environments or use your own Fortran compiler / interpreter / IDE.