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