Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
CUSTOMER_CODE SMUDE DIVISION_CODE SMUDE EVENT_CODE APR2016 ASSESSMENT_CODE BCA4020_APR2016 QUESTION_TYPE DESCRIPTIVE_QUESTION QUESTION_ID 72590 QUESTION_TEXT What is inheritance? Explain the types of relationships supported in Java inheritance with example. Inheritance is one of the cornerstones of object-oriented programming, because it allows the creation of hierarchical classifications. Using inheritance, you can create a general class that defines traits common to a set of related items. This class can then be inherited by other, more specific classes, each adding those things that are unique to it. In the terminology of Java, a class that is inherited is called a superclass. The class that does the inheriting is called a subclass. Therefore, a subclass is a specialized version of a superclass. It inherits all of the instance variables and methods defined by the superclass and add its own, unique elements. (1 mark) Types of Relationships Relationships are classified as follows: SCHEME OF EVALUATION A Kind-Of relationship A Is-A relationship A Part-Of-relationship A Has-A relationship (For each point with explanation and example – 2 marks) QUESTION_TYPE DESCRIPTIVE_QUESTION QUESTION_ID 72593 QUESTION_TEXT What are the various methods available in RemoteObject class. * RemoteArray * RemoteBoolean * RemoteByte * RemoteChar * RemoteClass * RemoteDouble * RemoteField * RemoteFloat SCHEME OF EVALUATION * RemoteInt * RemoteLong * RemoteShort * RemoteString * RemoteThread * RemoteThreadGroup * RemoteValue Any 10 methods = 10 marks. (1* 10 =Total 10 marks) QUESTION_TYPE DESCRIPTIVE_QUESTION QUESTION_ID 120578 QUESTION_TEXT What is a package in Java? How do you define a package in Java? Explain the class member access permissions in Java. Java provides a mechanism for partitioning the class name space into more manageable chunks. This mechanism is the package. The package is both a naming and a visibility control mechanism. (1 Mark) Defining a Package: SCHEME OF EVALUATION Include a package command as the first statement in a Java source file. Any classes declared within that file will belong to the specified package. The package statement defines a name space in which classes are stored. If you omit the package statement, the class names are put into the default package, which has no name. The general form of the package statement: package pkg; Here, pkg is the name of the package For example, the following statement creates a package called MyPackage. package MyPackage; We can create a hierarchy of packages. To do so, simply separate each package name from the one above it by use of a period The general form of a multileveled package statement is : package pkg1[.pkg2[.pkg3]]; For example, a package declared as package java.awt.image; needs to be stored in java/awt/image, java\\awt\\image, or java:awt:image on your UNIX, Windows, or Macintosh file system, respectively. (4 Marks) Access Protection: (5 marks) QUESTION_TYPE DESCRIPTIVE_QUESTION QUESTION_ID 120581 a. What are the rules for overriding a method in Java? b. Write any three uses of Inheritance. QUESTION_TEXT a. SCHEME OF EVALUATION 1. The method name and the order of arguments should be identical to that of the superclass method. 2. The return type of both the methods must be the same. 3. The overriding method cannot be less accessible than the method it overrides. 4. An overriding method cannot raise more exceptions that those raised by the superclass. b. 1. Inheritance reduces redundancy in code. Code redundancy means writing the same code in different places, leading to unnecessary replication of code. Inheritance helps you to reuse the code. 2. Maintain code easily, as the code resides at one place. Any changes made to the superclass automatically change the behavior of the subclass. 3. Extend the functionality of an existing class by adding more methods to the subclass. (10 marks) QUESTION_TYPE DESCRIPTIVE_QUESTION QUESTION_ID 120582 QUESTION_TEXT What is Java IDL? Explain. 1. Java IDL is a technology for distributed objects – i.e. objects interacting on different platform across a network. IDL stands for Interface Definition Language. 2. Java IDL is similar to RMI, which supports distributed objects written entirely in the Java programming language. SCHEME OF EVALUATION However, Java IDL enable objects interact regardless of whether they’re written in the Java programming language or another language such as C, C++, COBOL or others. 3. Java IDL is based on the Common Object Request Brokerage Architecture, an industry standard distributed object model. 4. A key feature of CORBA is IDL, a language –neutral Interface Definition Language. Each language that supports CORBA has its own IDL mapping and as its name implies, Java IDL supports the mapping for Java. CORBA and the IDL mappings are the work of an industry consortium known as the OMG or Object Management Group. 5. TO support interaction between objects in separate programs Java IDL provides an Object Request Broker, or ORB. The Orb is a class library that enables low level communication between Java IDL applications and other CORBA compliant applications. (10 marks) QUESTION_TYPE DESCRIPTIVE_QUESTION QUESTION_ID 120583 Write a note on following, give example for each QUESTION_TEXT a. Break statement b. Continue statement a. Break statement: By using break, you can force immediate termination of loop, bypassing the conditional expression and any remaining code in the body of the loop. When a break statement is encountered inside a loop, the loop is terminated and program control resumes at the next statement following the loop. (3 marks) Ex: //Using break to exit a loop SCHEME OF EVALUATION class BreakLoop{ public static void main(String args[ ]) { for(int i=0; i<100; i++){ if(I == 10) break; // terminate loop if i is 10 system.out.println(“Loop complete.”); } } (2 marks) b. Continue statement: sometimes it is useful to force an early iteration of a loop. that is, you might want to continue running the loop, but stop processing the remainder of the code in its body for this particular iteration…..(3 marks) ex: //Demonstrate continue. class Continue{ public static void main (String args[ ]) { for (int i=0; i<10; i++) { System.out.print (i+ “ “); if (i%2 == 0) continue; Sytem.out.println(“”); } } } (2 marks)