Object-Oriented Design - Java Software Solutions: Foundations of Program Design - page 322

Often, the this reference is used to distinguish the parameters of a constructor
from their corresponding instance variables with the same names. For example,
the constructor of the Account class was presented in Chapter 4 as follows:
public Account (String owner, long account, double initial)
{
name = owner;
acctNumber = account;
balance = initial;
}
When writing this constructor, we deliberately came up with different names for
the parameters to distinguish them from the instance variables name , acctNumber ,
and balance . This distinction is arbitrary. The constructor could have been writ-
ten as follows using the this reference:
public Account (String name, long acctNumber, double balance)
{
this .name = name;
this .acctNumber = acctNumber;
this .balance = balance;
}
In this version of the constructor, the this reference specifically refers to the
instance variables of the object. The variables on the right-hand side of the assign-
ment statements refer to the formal parameters. This approach eliminates the need
to come up with different yet equivalent names. This situation sometimes occurs
in other methods but comes up often in constructors.
SELF-REVIEW QUESTIONS (see answers in Appendix N)
SR 7.10 Describe a dependency relationship between two classes.
SR 7.11 Explain how a class can have an association with itself.
SR 7.12 What is an aggregate object?
SR 7.13 What does the this reference refer to?
7.5 Interfaces
We've used the term interface to refer to the set of public methods through which
we can interact with an object. That definition is consistent with our use of it in
this section, but now we are going to formalize this concept using a particular
language construct in Java.