Classes - Multimedia Introduction to Programming Using Java - page 109

inside-out rule , which in this instance makes the use of this unnecessary. Here
is the general rule:

General inside-out rule : In a subpart (e.g. a method) of a con-
struct (e.g. a class), all the names that are declared or that can be
referenced in the construct can be referenced in the subpart,
unless the subpart redeclares them.

Here is the inside-out rule as it pertains to method bodies in Java:

Inside-out rule for non-static method bodies : In a method body,
all the components of the class in which the method is defined can
be referenced, unless they are redeclared (e.g. as parameters).

This inside-out rule in Java lets us write method toString more simply as:
/** = a representation of this instance */
public String toString() {
return getName() + ", year " + getStart();

}
because getName , year , and getStart are declared in class Employee .
We illustrate a case where the use of this is necessary. Consider writing
method setName using name for the parameter instead of n :
/** Set the name of this Employee to name */
public void setName(String name)
{ this .name= name; }
Since the parameter is named name , name cannot be used directly to refer to
field name . The assignment name= name; assigns to the parameter and not to the
field. To assign to the field, write the assignment as: this .name= name;
Some programmers use the convention that in a setter method, the parame-
ter name is the same as the field being set. When using this convention, the use
of keyword this is needed to assign to the field.

3.1.3 Declaration of constructors

Chapter 2 contains an extensive treatment of procedures and functions. Here, we
discuss the third kind of method, the constructor . There is one constructor in
class Employee , which we give here:
/** Constructor: a person with name n , year hired d , salary 50,000 */
public Employee(String n, int d) {
name= n;
start= d;

Activity
3-5.2

}