General

What Is Windows DNA? Microsoft® Windows® Distributed interNet Applications Architecture (Windows DNA) is the application development model for the Windows platform. Windows DNA specifies how to: develop robust, scalable, distributed applications using the Windows platform; extend existing data and external applications to support the Internet; and support a wide range of client devices maximizing the reach of an application. Because Windows DNA relies on a comprehensive and integrated set of services provided by the Windows platform, developers are free from the burden of building or assembling the required infrastructure for distributed applications and can focus on delivering business solutions. Windows DNA addresses requirements at all tiers of modern distributed applications: presentation, business logic, and data. Like the familiar PC environment, Windows DNA enables developers to build tightly integrated applications by accessing a rich set of application services in the Windows platform using a wide range of familiar tools. These services are exposed in a unified way through the Component Object Model (COM). Windows DNA provides customers with a roadmap for creating successful solutions that build on their existing computing investments and will take them into the future. Using Windows DNA, any developer will be able to build or extend existing applications to combine the power and richness of the PC, the robustness of client/server computing, and the universal reach and global communications capabilities of the Internet. Q - What is an interface? A - An interface is nothing more than a defined set of public methods and properties (which are really methods, also) that are supported by an object. More than one type of object can support the same interface (for e.g., Textboxes and ComboBoxes are both Controls) and an object can support more than one interface (a Textbox is both a Textbox and a Control). Interfaces serve as a contract between the creator of an object and the user of that object. Any object which supports an interface is required to provide each and every property and method that makes up that interface. Q - What is inheritance? A – Inheritance is one of the three pillars of object-oriented theory. Inheritance refers to the concept of deriving new objects from existing ones. This creates "is a type of" relationships between the objects. Generally this works along the lines of specific object A is a type of general object B (i.e. object "Poodle" is a type of "Dog" object). This classifying of objects into base types and sub types is also referred to as abstraction. Inheritance can also take on different meanings. There is implementation inheritance (sometimes called "true" inheritance), where a derived object inherits the behavior (method) of its parent(s). The derived object may use this behavior or in some cases may define its own behavior for selected methods. Interface inheritance, on the other hand, involves a derived object sharing the same interface as its parent. With interface inheritance, the derived class is responsible for providing its own implementation for each inherited method. Q - What is Encapsulation? A - Encapsulation is one of the three pillars of object-oriented theory. It refers to hiding or protecting implementation details (such as data) within an object, only exposing that which is necessary, and controlling access (for example, providing functions to get and set data values, rather than providing direct access to variables). Essentially, proper encapsulation makes an object a "black box". The user of the object provides the required input and receives an expected output, but has no "under the hood" knowledge of how the object works. Q - What is polymorphism? A - Polymorphism is one of the three pillars of object-oriented theory. In essence, it means that objects can be more than one type of thing. We see this every day in life: a two-seat convertible is a type of car, which is a type of vehicle. The same concept that applies to physical objects can also be applied to software objects. Code that expects a parameter of type car should work equally well with our two-seater or a station wagon. This allows us to write code that is either specific or abstract, depending on our needs. Polymorphism is the ability to override the behavior of the base class.

Q - What is an hWnd and what can it be used for? A - An hWnd is a Handle to a Window. A handle is a long integer generated by the operating system so it can keep track of the all the objects (a form, a command button etc.). You can't set an hWnd at design or runtime, and the value of the handle changes each time the form is opened. Handles are used when you make calls to API functions; the function needs to know the handle of the window, plus other arguments depending on what the API does. Declare Function GetWindowText Lib "user32" alias _ "GetWindowTextA" (byval Hwnd as long, byval lpstring as string, byval cch as long) as Long Q. What is the difference between non-virtual and virtual functions? A. The behavior of a non-virtual function is known at compile time while the behavior of a virtual function is not known until the run time. Q. What is a pure virtual function? A. It is a member function without implementation. Q. What is an abstract base class? A. It is a class that has one or more pure virtual functions. Q. What is the difference between function overloading and function overriding? A. Overloading is a method that allows defining multiple member functions with the same name but different signatures. The compiler will pick the correct function based on the signature. Overriding is a method that allows the derived class to redefine the behavior of member functions which the derived class inherits from a base class. The signatures of both base class member function and derived class member function are the same; however, the implementation and, therefore, the behavior will differ. Q. What is function's signature? A. Function's signature is its name plus the number and types of the parameters it accepts. # A thread is a set of one or more instructions given by a task (application) to a CPU. In a sense, every time you run an application, you can think of that application instance running in memory as a thread. # Concurrency is the existence of more than one request for the same object at the same time. When object or component concurrency occurs, a locking mechanism is necessary to serialize requests. Serializing requests means that the object or component handling the request only one request at a time. # A class is an abstract entity (a “thing” that carries out a subset of your user’s requirements) with behaviors (a set of functions or methods) and attributes (variables or properties that identify the class). Class defines the behavior and identity of objects. Some classes can also define the behavior and identity of other classes. Such classes are called base classes. Base classes that can’t be instantiated into concrete objects are called abstract classes. SDLC The life cycle begins when an application is first conceived and ends when it is no longer in use. It includes aspects such as initial concept, requirements analysis, functional design, internal design, documentation planning, test planning, coding, document preparation, integration, testing, maintenance, updates, retesting, phase-out, and other aspects. Small to Medium database software projects are generally broken down into six stages: 1. Project Planning 2. Requirement Definitions 3. Design 4. Development 5. Integration and Test 6. Installation and Acceptance

The relationship of each stage to the others can be roughly described as a waterfall, where the outputs from the specific stage serve as the initial inputs for the following stage. During each stage, additional information is gathered or developed combined with inputs, and used to produce the stage deliverables. Software Testing What is 'Software Quality Assurance'? Software QA involves the entire software development PROCESS - monitoring and improving the process, making sure that any agreed-upon standards and procedures are followed, and ensuring that problems are found and dealt with. It is oriented to 'prevention'. What is 'Software Testing'? Testing involves operation of a system or application under controlled conditions and evaluating the results. Testing is the process of examining an application to ensure it fulfills the requirements for which it was designed and meets quality expectations. More importantly, testing ensures the application meets customer expectations. Testing accomplishes a variety of things, but most importantly it measures the quality of the software you are developing. Glass Box Testing (also known as Structural Testing or Clear Box Testing or White Box Testing) focuses on the inside of the “box” or relying on the internal knowledge of the system as a method for testing. Knowledge of the code is not needed during glass box testing. Glass box testing has several variations of testing, one of which is static and dynamic analysis where techniques are used to facilitate the execution of the software product being tested. Dynamic analysis is the testing portion that involves running the system. This type of testing can be used when testing a software product such as database of college students, courses they are registered for academic status, gender, social security number, address, etc. There are several different types of static techniques. Statement Coverage testing is performed by executing every statement at least once. Branch Coverage testing is performed by running a series of tests or test cases to ensure that all branches of a test requirement or software component are tested at least once. Path Coverage testing is performed by testing all the various paths of each test requirement or software component. There are several advantages of Glass Box testing such as: • It forces the tester to use reason when testing the software. It approximates the partitioning performed by execution equivalence. It reveals all errors in the “hidden” code. • It reveals optimizations. The disadvantages of Glass box testing are: • It is expensive. • A tester may miss cases omitted in the code. Black Box Testing (also known as Behavioral, Functional, Closed Box, and Opaque Box) focuses on testing the functionality of the system, using functional requirements if available. Black box testing treats the system as a “black box”. This type of testing is based solely on system requirements. This type of testing can be used when testing a order tracking system such as purchasing a product over the Internet which involves creating a user account, selecting items to purchase, entering personal information, and entering payment information, where all functionality stated in the requirements has to be met before the software product is ready for production, i.e. one requirement would be a user has to able to select an item to purchase and have the ability to select additional items to purchase or delete the items currently in the shopping cart. Unit Testing takes the smallest piece of testable software in the application, isolate it from the remainder of the code, and determine whether it behaves exactly as you expect. Each unit is tested separately before integrating them into modules to test the interfaces between modules. Unit testing has proven its value in that a large percentage of defects are identified during its use.

The most common approach to unit testing requires drivers and stubs to be written. The driver simulates a calling unit and the stub simulates a called unit. The investment of developer time in this activity sometimes results in demoting unit testing to a lower level of priority and that is almost always a mistake. Even though the drivers and stubs cost time and money, unit testing provides some undeniable advantages. It allows for automation of the testing process, reduces difficulties of discovering errors contained in more complex pieces of the application, and test coverage is often enhanced because attention is given to each unit. Integration Testing is a logical extension of unit testing. In its simplest form, two units that have already been tested are combined into a component and the interface between them is tested. A component, in this sense, refers to an integrated aggregate of more than one unit. In a realistic scenario, many units are combined into components, which are in turn aggregated into even larger parts of the program. The idea is to test combinations of pieces and eventually expand the process to test your modules with those of other groups. Eventually all the modules making up a process are tested together. Beyond that, if the program is composed of more than one process, they should be tested in pairs rather than all at once. Integration testing identifies problems that occur when units are combined. By using a test plan that requires you to test each unit and ensure the viability of each before combining units, you know that any errors discovered when combining units are likely related to the interface between units. This method reduces the number of possibilities to a far simpler level of analysis. Regression Testing ensures that no anomalies appear in the system due to changes made. This involves testing any modifications made to the system to ensure no new anomalies are found. An example of this type of testing would be to test a shopping cart feature of an order tracking system by using an existing user and purchasing additional products and purchasing products as a new user ensuring that all the key functionality of the system is tested. System Testing allows the tester to prove that the system meets all objectives and requirements. System testing is a sort of verification process and provides an external view of the system. This type of testing should be approached in a manner that would be easy for user to use since they are not concerned with how the system works the system responses and the interface. The user only wishes to know that the system functions properly. System Testing verifies the system when the testing occurs in a non-live test environment using non-live test data and could also be referred to as verification testing. An IT group consisting of testers, developers, end users, and operations staff usually performs system testing. This type of testing would ensure that the software product operates in various operating systems, various Internet browsers, various Internet speed, and various resolutions. CMM What is the CMM? It is a model that describes how software engineering practices in an organization evolve under certain conditions: 1. The work performed is organized and viewed as a process 2. The evolution of the process is managed systematically What are the four principles underlying the CMM? 1. Evolution is possible and takes time 2. Process maturity can be defined in distinguishable stages 3. Process evolution implies that some things must be done before others 4. Maturity will erode unless it is sustained The Capability Maturity Model (CMM) is a methodology used to develop and refine an organization's software development process. The model describes a five-level evolutionary path of increasingly organized and systematically more mature processes. CMM was developed and is promoted by the Software Engineering Institute (SEI), a research and development center sponsored by the U.S. Department of Defense (DoD). SEI was founded in 1984 to address

software engineering issues and, in a broad sense, to advance software engineering methodologies. More specifically, SEI was established to optimize the process of developing, acquiring, and maintaining heavily software-reliant systems for the DoD. Because the processes involved are equally applicable to the software industry as a whole, SEI advocates industry-wide adoption of the CMM. The CMM is similar to ISO 9001, one of the ISO 9000 series of standards specified by the International Organization for Standardization (ISO). The ISO 9000 standards specify an effective quality system for manufacturing and service industries; ISO 9001 deals specifically with software development and maintenance. The main difference between the two systems lies in their respective purposes: ISO 9001 specifies a minimal acceptable quality level for software processes, while the CMM establishes a framework for continuous process improvement and is more explicit than the ISO standard in defining the means to be employed to that end. CMM's Five Maturity Levels of Software Processes • At the initial level, processes are disorganized, even chaotic. Success is likely to depend on individual efforts, and is not considered to be repeatable, because processes would not be sufficiently defined and documented to allow them to be replicated. The software process is characterized as ad hoc, and occasionally even chaotic. Few processes are defined, and success depends on individual effort and heroics • At the repeatable level, basic project management techniques are established, and successes could be repeated, because the requisite processes would have been made established, defined, and documented. Basic project management processes are established to track cost, schedule, and functionality. The necessary process discipline is in place to repeat earlier successes on projects with similar applications. • At the defined level, an organization has developed its own standard software process through greater attention to documentation, standardization, and integration. The software process for both management and engineering activities is documented, standardized, and integrated into a standard software process for the organization. All projects use an approved, tailored version of the organization's standard software process for developing and maintaining software • At the managed level, an organization monitors and controls its own processes through data collection and analysis. Detailed measures of the software process and product quality are collected. Both the software process and products are quantitatively understood and controlled. • At the optimizing level, processes are constantly being improved through monitoring feedback from current processes and introducing innovative processes to better serve the organization's particular needs.