Question

6 Marks Question 2 This question is related to Human Computer Interaction (HCI) (a) Explain what is meant by the term "user centred design". How can it be best achieved? (2 marks) (b) Which of Shneiderman and Plaisant's 8 golden rules for interface design do you consider to be the most important? Explain your answer. (2 marks) What data entry methods should be employed (if possible) in a user interface (c) that aims to minimise errors arising from invalid data entry? (2 marks) Question 3 5 Marks Java provides a basic for statement (with an explicit iterator) and an enhanced (a) for statement (with no explicit iterator). When would you use an enhanced for statement in preference to a basic for statement? Explain your answer. (2 marks) (b) Explain why two int values are compared for equality using the relational Operator, whereas for testing string equality, the String . equals () (3 marks) method is used.

Answer 1

3.

a)

If you are working with arrays and collections, you can use alternative syntax of for loop (enhanced form of for loop) to iterate through items of arrays/collections. It is also referred as for-each loop because the loop iterates through each element of array/collection.

Example:

class AssignmentOperator {
   public static void main(String[] args) {
      
      char[] vowels = {'a', 'e', 'i', 'o', 'u'};
      // foreach loop
      for (char item: vowels) {
         System.out.println(item);
      }
   }
}

The output of both programs will be same:

a
e
i
o
u

b)

Double equals operator (==) is used to compare two or more than two objects, If they are referring to the same object then return true, otherwise return false. Since integers refer to the same object, we can compare them using ==.

In Java, string equals() method compares the two given strings based on the data / content of the string. If all the contents of both the strings are same then it returns true. If all characters are not matched then it returns false.

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