1. Reading inputs from the terminal

In Fortran, you can also use the asterisk * to take inputs from the terminal shell. For example, to ask a question and read the answer, we can use:

program AskQuestions

INTEGER       :: ID
CHARACTER(16) :: Hometown

write(*,*) 'What is your Student ID?'
read(*,*) ID
write(*,*) 'You entered ', ID

write(*,*) 'Where is your hometown?'
read(*,*) Hometown
write(*,*) 'You entered ', Hometown

end program AskQuestions

Compile and run the above program.

2. Find the largest real value

Write a Fortran program to find approximately the largest value that can be stored in a real(4) variable.

[Hint:] You might, for example, repeatedly multiply a variable the power of 2 within a loop, printing the new value on the terminal, until the computer gives up.

Change the real variable form real(4) to real(8), check what happens.

3. Set a password

Write a Fortran program SetPassWord.f90:

3.1. First, the program asks you to enter a 4-digit code as the password.

3.2. Second, the program asks you to re-type the password again.

3.3. If you type the same password in 3.1 and 3.2, the program will end and print some success messages.

3.4. Otherwise, it will print some error messages and ask you to retype again. If you have failed three times, the program will be terminated with error messages.