Information Technology Reference
In-Depth Information
Figure 5-9 illustrates the following about the values of the actual and formal parameters at
various stages in the execution of the method:
Before the method call, variables
A1
and
A2
, which will be used as the actual parameters,
are already on the stack.
At the beginning of the method, the names of the formal parameters are set as aliases for
the actual parameters. Variables
A1
and
f1
refer to the same memory location, and
A2
and
f2
refer to the same memory location. The
names
A1
and
A2
are out of scope and can-
not be accessed from inside the method.
Inside the method, the code creates an object of type
MyClass
and assigns it to
f1
. It then
assigns a value to
f1
's field and also assigns a value to
f2
. The assignment to
f1
and
f2
are
both required, since they are output parameters.
After method execution, the names of the formal parameters are out of scope, but the
values of both
A1
, the reference type, and
A2
, the value type, have been changed by the
activity in the method.
Figure 5-9.
Output parameters
