Computer programming

Question

Answer the following Questions:

1. What is a user interface?

2. What is an event-driven program?

3. List some of the Common GUI components?

4. What is an object?

5. Discuss the features of encapsulation, polymorphism and inheritance?

6. What is the difference between public method and private method?

7. What is an access specifier? What access specifier is commonly used with a class’s fields?

8. What does the New key word do?

9. What is an accessor? What is a mutator?

Answer 1

1) Forms that allow user to input data and/or present

results to the user

2) Windows application in which EVENTS control the flow of

the program. Button clicks, scrolling, mouse clicks, drag and drop,

timers,

3) Buttons, check boxes, radio option buttons, scroll bars,

list boxes, combo boxes, dialog boxes, labels, menus,

group containers, sliders, spin buttons, picture and image boxes,

timers, and various other 3rd party controls

4) A collection of data and subroutine methods that operate on

the data, treated and used as a simple

5) Encapsulation: the treatment and usage of a set of data,

along with subroutine methods that operate on the data;

a CLASS is a "blueprint" or "prototype" that defines the

data and method operators

Polymorphism: subroutines that have the ability to use variables

of different types at different times. A routine that

can have the same name but different parameters and arguments;

a routine that performs the SAME operation independent of

data type

a classic example of polymorphism is the SORT() routine. Sort routine

will sort an array of any type

Sort( Array, # of records, record size, compareFunc)

Inheritance:

the ability to create a new class from existing classes. The inherited

class can access data members from the parent classes, as well as

have new one's of it's own.

6) Public: the member is available can be read/written to anywhere in the program

Private: the member can only be accessed by methods of the same class

Protected: the member can only be accessed by method of the same class OR

by inherited classes

7) Access Specifier declares the member as public, private or protected

8) New keyword allocates memory for object(s) and calls the constructor

9) Accessor a.k.a Getter method: returns the VALUE of private member

to the caller. However, if the caller then changes the value, the original

is not changed

Mutator a.k.a. Setter method: allows the caller to actually change, or

Update the value within of the private member