2. Parameters



Answer:
    A parameter is a value that is sent to a method when it is called.
    


    

    Parameters
    

    

    
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.
    

    


    


    Question 2:
    1. Will the instance variable balance of the object hold its value permanently?
    2. Will the parameter amount of the object's method hold its value permanently?