1. Prototype:Specify the kinds of objects to create using a prototypical instance, and create new objects by copying this prototype.
2. Proxy: Provide a surrogate or placeholder for another object to control access to it.
3. Singleton: Ensure a class has only one instance, and provide a point of access to it.
4. State: Allow an object to alter its behavior when its internal state changes. the object will appear to change its class.
5. Strategy:Define a family of algorithms, encapsulate each one, and make them interchangeable. Strategy lets the algorithm vary independently from clients that use it.
6. Template Method:Define the Skelton of an operation, deferring some steps to subclasses. Template method subclasses redefine certain steps of an algorithm without changing the algorithms structure.
7. Visitor: Represent an operation to be performed on the elements of an object structure. Visitor lets you define a new operation without changing the classes of the elements on which it operates.
8. What is a purpose of Creational patterns?
concern the process of object creation
9. What is a purpose of Structural patterns?
the composition of classes or objects
10. What is a purpose of Behavioral patterns?
characterize the ways in which classes or objects interact and distribute responsibility
11. Define class inheritance ?
class inheritance defines an object’s implementation in terms of another object’s implementation (code and representation sharing
12. Define interface inheritance ?
interface inheritance (or subtyping) describes when an object can be used in place of another
13. Expand MVC:____________________________________________
MVC consists of three kinds of objects.
M->>MODEL is the Application object.
V->>View is the screen presentation.
C->>Controller is the way the user interface reacts to user input.
14. Explain White-box reuse
Reuse by subclassing (class inheritance)
Internals of parent classes are often visible to subclasses
works statically, compile-time approach
Inheritance breaks encapsulation
15. Explain Black-box reuse
Reuse by object composition
Requires objects to have well-defined interfaces
No internal details of objects are visible
16. What is delegation ?
Two objects are involved in handling a request: a receiving object delegates operations to its delegate
17. What is Framework?
A framework is a set of cooperating classes that make up a reusable design for a specific class of software
18. Document Structure:
The choice of internal representation for the document affects nearly every aspect of Lexis's design. All editing , formatting, displaying, and textual analysis will require traversing the representation.
How does Lexi actually arrange text and graphics into lines and columns?
What objects are responsible for carrying out different formatting policies?
20. How do these policies interact with the document’s internal representation?
Embellishing the user interface:
Lexis user interface include scroll bar, borders and drop shadows that embellish the WYSIWYG document interface. Such embellishments are likely to change as Lexis user interface evolves.