Java Reference
In-Depth Information
Figure 8
The Implicit Parameter of a Method Call
108
109
S
ELF
C
HECK
15.
How many implicit and explicit parameters does the
withdraw
method of the
BankAccount
class have, and what are their names and
types?
16.
In the
deposit
method, what is the meaning of
this.amount
? Or,
if the expression has no meaning, why not?
17.
How many implicit and explicit parameters does the
main
method of
the
BankAccount-Tester
class have, and what are they called?
C
OMMON
E
RROR
3.2: Trying to Call a Method Without
an Implicit Parameter
Suppose your
main
method contains the instruction
withdraw(30); // Error
The compiler will not know which account to access to withdraw the money. You
need to supply an object reference of type
BankAccount
:
BankAccount harrysChecking = new BankAccount();
harrysChecking.withdraw(30);