Question

Questions 5 - 7 refer to the following code: public class Whatchamacallit { private double price; private String title; public Whatchamacallit() { this (0, "none"); } public Whatchamacallit(double p, String t) { price = 0; if (p > 0) { price = p; } title = t; } public String toString() { return title + " costs $" + price; } } The following code segment appears in another class: ArrayList list = new ArrayList(); list.add(new Whatchamacallit()); list.add(new Whatchamacallit(3.5, "book")); list.add(new Whatchamacallit(-17, "CD")); list.add(new Whatchamacallit(18.95, "sweater")); list.add(new Whatchamacallit(5, "notebook")); /* Missing Code */ Suppose the following line is used to replace /* Missing Code */. System.out.println(list.get(0)); What is printed as a result of executing the code segment?

Answer 1

Some code formatting is required to understand this question

Whatchamacallit {
   private double price;
   private String title;
   public Whatchamacallit()
   {
     this (0, "none");
   }
   public Whatchamacallit(double p, String t)
   {
     price = 0;
     if (p > 0)
     {
         price = p;
      }
      title = t;
    }
  public String toString()
   { return title + " costs $" + price; }
}

The following code segment appears in another class:

  ArrayList list = new ArrayList();
  list.add(new Whatchamacallit());
  list.add(new Whatchamacallit(3.5, "book"));
  list.add(new Whatchamacallit(-17, "CD"));
  list.add(new Whatchamacallit(18.95, "sweater"));
   list.add(new Whatchamacallit(5, "notebook"));
  /* Missing Code */
Suppose the following line is used to replace /* Missing Code */. System.out.println(list.get(0)); 

The answer is 'none costs $0'

This is because the line:
'System.out.println(list.get(0))'
gets the first item (index 0) in the array, which was :
'list.add(new Whatchamacallit()) '
and Whatchamacallit() sets price = 0 and title = 'none' in the class Whatchamacallit

The specific output of the  'get(0)' is because of the 'toString()' method in 
Whatchamacallit