
Do not declare the parame-
ters of a method inside the
method body. When the
method begins executing,
the parameters exist and
have been assigned the
values set by the client in
the method call.
COMMON ERROR
TRAP
Be aware that a method
parameter or local variable
that has the same name as
an instance variable hides
the instance variable.
COMMON ERROR
TRAP
7.7 Writing Data Manipulation Methods 393
for the parameter. To avoid name conflicts, we name each parameter using the
pattern newInstanceVariable.
A similar common error is to declare a local variable with the same name as
the instance variable, as shown in the following incorrectly coded method:
// Incorrect! ...