Software Patterns, Creational

Question 1

Abstract factory

Answer 1

Provide an interface for creating families of related or dependent objects without specifying their concrete classes.

Question 2

Builder

Answer 2

Separate the construction of a complex object from its representation allowing the same construction process to create various representations.
And hep against tunneling constructors with 5 parameters.

Question 3

Factory method

Answer 3

Define an interface for creating a single object, but let subclasses decide which class to instantiate. Factory Method lets a class defer instantiation to subclasses

Question 4

Lazy initialization

Answer 4

Tactic of delaying the creation of an object, the calculation of a value, or some other expensive process until the first time it is needed. This pattern appears in the GoF catalog as “virtual proxy”, an implementation strategy for the Proxy pattern.

Question 5

-Multiton

Answer 5

Ensure a class has only named instances, and provide global point of access to them.

Question 6

-Object pool

Answer 6

Avoid expensive acquisition and release of resources by recycling objects that are no longer in use. Can be considered a generalisation of connection pool and thread pool patterns.

Question 7

Prototype

Answer 7

Specify the kinds of objects to create using a prototypical instance, and create new objects by copying this prototype.

Question 8

-Resource acquisition is initialization

Answer 8

Ensure that resources are properly released by tying them to the lifespan of suitable objects.

Question 9

Singleton

Answer 9

Ensure a class has only one instance, and provide a global point of access to it.