A parameter is a value that is sent to a method when it is called.
Here is an example of a method that uses a parameter.
public class CheckingAccount
{
. . . .
private int balance;
. . . .
public void processDeposit( int amount )
{
balance = balance + amount ;
}
}
The parameter amount is used by a caller to send a
value to the method.
This is called passing a value into the method.
Here is part of a main() method that uses the parameter to
pass a value into the processDeposit() method of an object:
public class CheckingAccountTester
{
public static void main( String[] args )
{
CheckingAccount bobsAccount = new CheckingAccount( "999", "Bob", 100 );
bobsAccount.processDeposit( 200 );
. . . . . .
}
}
When the statement
bobsAccount.processDeposit( 200 );
is executed,
the parameter amount is given
the value 200.
Now, as the processDeposit method executes,
that value is added to the object's instance variable balance:
balance = balance + amount ;
Then the method finishes and control returns to main().
The balance of the bobsAccount object has
been changed.
balance of the object
hold its value permanently?amount of the object's method
hold its value permanently?