Technology Questions

An abstract class is an incomplete class. An abstract class is defined with the keyword abstract . We cannot create an object of the abstract class because it is not complete. It sets a behavioral protocol for all its child classes.

Pass By Reference means the passing the address itself rather than passing the value. Passby Value means passing a copy of the value to be passed.

Adb is short for Android Debug Bridge. It allows developers the power to execute remote shell commands. Its basic function is to allow and control communication towards and from the emulator port.

The android system will keep all the process that are hosting the services together at one place till the time the service is not started or connected to the client. The priority of the process is divided when running low on memory or when the process has to be killed. The process lifecycle is as follows:
- The service is running currently then the methods onCreate(), onStartCommand(), and onDestroy()methods, will run in the foreground to execute the process without being killed.
- The service is already started then the process can be considered as less important then the processes that are currently visible and used. This is done as there are only few processes that are visible to the users on the screen.
- The clients are bounded to the services they are providing requires more priority in the execution list.
- The service that is started uses startForeground(int, Notification)API to allow all the services to run in the foreground state. The system considers only the services where the user is still active as the services not to be killed.

Use Interfaces when…

- You see that something in your design will change frequently.

- If various implementations only share method signatures then it is better to use Interfaces.

- You need some classes to use some methods which you don't want to be included in the class, then you go for the interface, which makes it easy to just implement and make use of the methods defined in the interface.

Use Abstract Class when…

- If various implementations are of the same kind and use common behavior or status then abstract class is better to use.

- When you want to provide a generalized form of abstraction and leave the implementation task with the inheriting subclass.

- Abstract classes are an excellent way to create planned inheritance hierarchies. They're also a good choice for nonleaf classes in class hierarchies.

1. Initialization
2. At selection-screen
3. Start-of-selection
4. End-of-selection
5. Top-of-page
6. End-of-page
7. At line-selection
8. At user-command
9. At PF
10. Get
11. At New
12. At LAST
13. AT END
14. AT FIRST

- To host a website a platform needs to be decided using which the hosting can be made simpler. 

- The specification needs to be determined before hosting the website and choosing the hosting platform. 

- The choice of operating system needs to be clear in choosing the website hosting services and the resources that the particular hosting platform requires need to be known. 

- The web hosting platform requires lots of services that need to be decided before hosting the website on the web.

- The space and the cost need to be kept minimum and according to that the choice has to be made between hosted or shared platforms.

If we print any object by using println() or print() methods.

The println() or print() methods internally calls tostring() method and prints the return value of toString() method.