balance
hold a permanent value?
balance
is part of the state of the object and will hold a
value as long as the object exists.amount
hold a permanent value?
amount
is used only to pass in a value to the method.
It does not have a permanent existance.The following definitions are useful:
amount
is a
formal parameter of processDeposit
200
used when processDeposit
is called is an actual parameter.When a method is called, the formal parameter is temporarily "bound" to the actual parameter. The method uses the formal parameter to stand for the actual value that the caller wants to be used.
For example, here
the processDeposit
method
uses the formal parameter amount
to stand for the actual value
used in the procedure call:
balance = balance + amount ;
Note: formal parameters are bound to an actual value only as long as their method is active. When a method returns to its caller, the formal parameters no longer contain any values. They cannot be used to store the state of an object.
What is used to store the state of an object?