Question

public class Item implements Comparable
{
private String name;
private double price;
/**
* Constructor for objects of class Item
* @param theName name of item
* @param thePrice price of item
*/
public Item(String theName, double thePrice)
{
name = theName;
price = thePrice;
}
  
/**
* gets the name
* @return name name of item
*/
public String getName()
{
return name;
}
  
/**
* gets price of item
* @return price price of item
*/
public double getPrice()
{
return price;
}
  
/**
* sets new name of item
* @param newName new name of item
*/
public void setName(String newName)
{
name = newName;
}
  
/**
* sets price of item
* @param newPrice new price of item
*/
public void setPrice(Double newPrice)
{
price = newPrice;
}
  
public int compareTo(Object otherObject)
{
Item other = (Item) otherObject;
if (this.getPrice() > other.getPrice())
{
return 1;
}
else if (this.getPrice() < other.getPrice())
{
return -1;
}
else if (this.getPrice() == other.getPrice())
{
return -1;
}
return 0;
  
}
}

In the compareTo method, what exactly does "this" refer to.

  

Answer 1

The code define a class named Item

Item has two class variables / attributes : a String name and a double price

In the method lines

  
public int compareTo(Object otherObject)
{
Item other = (Item) otherObject;
if (this.getPrice() > other.getPrice())

this refers to the object that will call this method. Let us make an object of class Item

Example

object1 = Item("pencil", 2) // this is a pencil of 2

Lets us make another object

object2 = Item("eraser", 5) // this is eraser of price 5

When we call object1.compareTo(object2) , this , will refer to object 1 having pencil and 2 .

In the following line :

if (this.getPrice() > other.getPrice())

this.getPrice() will yield 2. Similarly other will refer to object 2 and other.getPrice() will yield value of 5

Conversely if object2.compareTo(object1) was called, then this would have referred to object 2

Short Answer : "this" refers to the object that is calling the method. "other" is the object being passed.