Problem solving and programming

procedure change(byVal a, byRef b)    a = a * 2    b = b + aendprocedure x = 3y = 4change(x, y)print(x)print(y)

State the outputs and explain the difference between passing by value and by reference.

function power(base, exp)    if exp == 0 then        return 1    else        return base * power(base, exp - 1)    endifendfunction

Rewrite power as an iterative function and compare the two versions.

Write a function validPassword(pw) that returns true only if the password is at least 10 characters long, contains at least one digit and at least one upper-case letter, and contains no spaces.

Write a class Account with private attributes accountNumber and balance, a constructor, a getBalance method and a withdraw(amount) method that only allows withdrawals that do not make the balance negative. Then write a subclass SavingsAccount that adds an interestRate attribute and an addInterest method.

Describe four features of an IDE that help programmers to find and fix errors.

Explain the difference between local and global variables and why local variables are preferred.

Describe a suitable data structure to store seat availability for one screening.

Describe a test plan for findSeats, including normal, boundary and erroneous data.

Tickets cost £12 for adults and £8 for children; screenings before 5pm are 25% cheaper; a group of 6 or more people gets £1 off each ticket. Write an algorithm to calculate the total price for a booking.

Evaluate the use of an object-oriented approach for developing the cinema booking system.