Associate Android Developer Certification Questions and Answer (Dumps and Practice Questions)
Question : Which of the following is not a valid Android resource file name?
1. mylayout.xml
2. myLayout.xml
3. my_layout.xml
4. mylayout1.xml
Correct Answer : 2
Explanation: Android file system is case-sensitive.
Make sure you type the exact names of your files in your code. the filename must only contain [a-z0-9_.], meaning lowercase alpha characters, numerals, underscores, and periods.
Capital letters are not allowed in naming any .xml files. using it will give you an error.
Why is the character set so limited
Because the name has to be a valid Java identifier, so you can use constants like R.layout.foo to identify the layout at runtime.
Which filenames are restricted - all of res? just res/layout? res/layout plus some other folders?
Anything in res/
Question : Which of these is not defined as a process state?
1. Non-visible
2. Visible
3. Foreground
4. Background
Correct Answer : 1
Explanation: To determine which processes should be killed when low on memory, Android places each process into an "importance hierarchy" based on the components running in them and the state of those components. These process types are (in order of importance):
A foreground process is one that is required for what the user is currently doing. Various application components can cause its containing process to be considered foreground in different ways. A process is considered to be in the foreground if any of the following conditions hold:
It is running an Activity at the top of the screen that the user is interacting with (its onResume() method has been called).
It has a BroadcastReceiver that is currently running (its BroadcastReceiver.onReceive() method is executing).
It has a Service that is currently executing code in one of its callbacks (Service.onCreate(), Service.onStart(), or Service.onDestroy()).
There will only ever be a few such processes in the system, and these will only be killed as a last resort if memory is so low that not even these processes can continue to run. Generally, at this point, the device has reached a memory paging state, so this action is required in order to keep the user interface responsive.
A visible process is one holding an Activity that is visible to the user on-screen but not in the foreground (its onPause() method has been called). This may occur, for example, if the foreground Activity is displayed as a dialog that allows the previous Activity to be seen behind it. Such a process is considered extremely important and will not be killed unless doing so is required to keep all foreground processes running.
A service process is one holding a Service that has been started with the startService() method. Though these processes are not directly visible to the user, they are generally doing things that the user cares about (such as background mp3 playback or background network data upload or download), so the system will always keep such processes running unless there is not enough memory to retain all foreground and visible process.
A background process is one holding an Activity that is not currently visible to the user (its onStop() method has been called). These processes have no direct impact on the user experience. Provided they implement their Activity life-cycle correctly (see Activity for more details), the system can kill such processes at any time to reclaim memory for one of the three previous processes types. Usually there are many of these processes running, so they are kept in an LRU list to ensure the process that was most recently seen by the user is the last to be killed when running low on memory.
An empty process is one that doesn't hold any active application components. The only reason to keep such a process around is as a cache to improve startup time the next time a component of its application needs to run. As such, the system will often kill these processes in order to balance overall system resources between these empty cached processes and the underlying kernel caches.
When deciding how to classify a process, the system will base its decision on the most important level found among all the components currently active in the process. See the Activity, Service, and BroadcastReceiver documentation for more detail on how each of these components contribute to the overall life-cycle of a process. The documentation for each of these classes describes in more detail how they impact the overall life-cycle of their application.
Question : What is the name of the folder that contains the R.java file?
1. src
2. res
3. bin
4. gen
Correct Answer : 4
Explanation: Android R.java is an auto-generated file by aapt (Android Asset Packaging Tool) that contains resource IDs for all the resources of res/ directory.
If you create any component in the activity_main.xml file, id for the corresponding component is automatically created in this file. This id can be used in the activity source file to perform any action on the component.
Related Questions
Question : Which of the following is not an Activity lifecycle call-back method?
1. onStart
2. onCreate
3. onPause
4. onBackPressed
Question : Which method is used to close an activity?
1. Destroy()
2. Finish()
3. Stop()
4. Close()
Question : Which of the following Activity life-cycle methods is called once the activity is no longer visible?
1. onStop
2. onPause
3. onDestroy
4. onHide
Question : Which of the following is a correct Android Manifest statement?
1.
2.
3.
4.
Question : Which of the following is true about attribute android:windowSoftInputMode of the
1. It specifies whether the window is in full screen or not
2. It adjusts how the main window of the activity interacts with keyboard
3. It adjusts how the window should be launched
4. It adjusts the window orientation
Question : Which of the following tools dumps system log messages including stack traces when the device or emulator throws an error?
1. DDMS
2. Logcat
3. Console
4. ADB