Quizz Master AISL year wednesday 26 october 2016

Transcription

1 Quizz Master AISL year wednesday 26 october 2016 First name : Second name : Some questions have more than one answer. Check all the good answers. The answers are in green. Objet oriented programming and the Java programming language What is JDK? a. A Java application b. The tools we can use to write computer programs with the Java langage c. The set of libraries given with the Java language d. Nothing related with Java What is JVM? a. A library for building softwares with the Java programming language b. A program which read Java byte code and execute it for the current machine c. A Java interpreter d. Nothing related with Java What are fundamental notions in OOP? a. Inheritance b. Polymorphism c. Sequential development d. Data hiding What is a Java class? a. A scheme for creating instances of the class b. A file without format c. A type representation built by a programmer d. A test code for some part of a software What are specific aspects of a constructor? a. The word void must be used as return type b. The Java compiler gives one in some cases which is removed in other cases c. It cannot be overloaded d. It is always used with the reserved keyword new 1/6

2 What is an interface? a. A concrete class b. A scheme which can have only declarations of methods and public static variables c. A tool to make multiple inheritance (grr!) d. A tool which indicates specifications which will have to be implemented For what the is made? a. To be used for the s b. A tool associated with the javadoc c. a tool to describe an error in the code d. Can be used to improve Java with annotations An annotation is a qualifier used by: a. only the Java compiler b. only the JVM c. only by execution environment d. by the three, Java compiler, JVM and execution environment The exceptions can be used: a. to treat exceptional cases by calling methods b. to have a good readability of the code c. to reroute a program to a code which is written to treat an exceptional circumstance d. to sort exceptional circumstances What is possible to do with exceptions? a. Put a finally block which will always be executed b. Use the word throws to redirect an exceptionnal treatment to the calling method c. Include try-catch block to treat the exception d. We must put a finally block Generic types a. can build sets of classes with types will be indicated later in the code b. can build ArrayList for objects of a precise class c. can allow multiple inheritance d. is nothing related with Java The garbage collector: a. can automatically build objects b. can delete objects which became unreferenced c. can automatically allocate objects at the beginning of a block d. can automatically deallocate objects at the end of a block 2/6

3 The inheritance a. can allow to obtain the whole methods and data members of a class b. can centralize in a class common methods and data members of other classes and so eliminate them in these classes c. can be multiple d. cannot be used with interfaces Polymorphism a. is only used at compilation step b. must have inheritance, method overriding and reference of base classes to be used c. allows to launch code without knowing which one at compile time d. allows to have methods with same name but different signatures in a class 3/6

4 UML : class diagram In this class diagram : 1st question : a. ArrayAdapter<T> is a generic class b. ArrayAdapter<T> extends the BaseAdapter class c. ArrayAdapter<T> implements the BaseAdapter interface d. ArrayAdapter<T> is an interface 2nd question : a. BaseAdapter is an abstract class b. BaseAdapter is a class which extends the two classes SpinnerAdapter and ListAdapter c. BaseAdapter is a class which implements the two interfaces SpinnerAdapter and ListAdapter d. BaseAdapter is a concrete class 3rd question : a. SpinnerAdapter and ListAdapter are two classes which inherit of the Adapter class b. SpinnerAdapter and ListAdapter are two interfaces which extend the Adapter interface c. SpinnerAdapter and ListAdapter are two interfaces which implement the Adapter interface d. SpinnerAdapter and ListAdapter are the two super-classes of BaseAdapter 4/6

5 4th question : a. Adapter extends AdapterView b. AdapterView extends Adapter c. AdapterView and Adapter are associated which means the name of one appears in the code of the other d. Adapter is an super-interface of the interfaces SpinnerAdapter and ListAdapter 5th question : a. AdapterView<T extends Adapter> is a generic class b. AdapterView<T extends Adapter> is an abstract class c. T extends Adapter means that the class put for T must extend Adapter d. T extends Adapter means that the class put for T must be a super class of Adapter 6th question : a. AbsSpinner is an interface b. AbsSpinner is a sub-class of AdapterView<T extends Adapter> c. AbsSpinner is an abstract class d. AbsSpinner is an object 7th question : a. AbsListView is both a ListView and a GridView b. ListViews and GridViews are AbsListViews c. The objects of the classes ListView ans GridView have the data and the methods of the AdapterView<T extends Adapter> class d. We can create objects of the classes ListView and GridView 5/6

6 Android 1 ) For Android, an AVD is : a. a driver for audio and video b. an emulator of smartphones c. an advanced library to build graphic user interfaces d. a debugger 2 ) A graphic user interface is defined in the main.xml file. This file is put in the res\layout. An activity can have this graphic user interface by the code: a. setcontentview("/res/layout/main.xml"); b. setcontentview("\res\layout\main.xml"); c. setcontentview(r.layout.main); d. setgui("main.xml"); 3 ) In this above main.xml file ci-dessus is declared <Button... android:id="@+id/my_button... />" To obtain this graphic component Button in the Java code of the activity which load this file main.xml, we must write: a. Button bt = (Button) findviewbyid(r.id.my_button); b. Button bt = (Button) findviewbyid(r.layout.my_button); c. Button bt = (Button) findviewbyid(r.main.my_button); d. Button bt = (Button) getguicomponent("my_button"); 4 ) The AndroidManifest.xml file of an Android app a. describes in xml the graphic user interface of this app b. describes the configuration of the Android app (permission to access internet, the declarations of activitys, etc.) c. describes treatments when errors occure d. can be omitted for some Android apps 5 ) The UI thread a. is the first launched thread b. is seldom used c. is for network communications d. is for client-serveur architectures 6/6