Abstract class: is a restricted class … Assembly language b. Answer: (d) A will be printed, and then an exception is thrown. 41) What is meant by the classes and objects that dependents on each other? Explain the life cycle of JDBC The life cycle for a servlet comprises of the following phases: • DriverManager : for managing a list of database drivers. C. primitive data type. Java MCQ Test. An abstract method is any method in an abstract class.. B. This section includes collections of multiple choice objective questions on fundamental and overview of Java language, Java tokens, keywords, identifiers, literals and operators, constants, variables and data types in Java, Operators and expressions, Control structure in Java, decision making and looping, definition of classes, objects and methods. MCQ 8: Which one of the following is true for Java. Home / Java Program / Array. Explanation: When a String is created using a new operator, it always created in the heap memory. Abstraction in Java. Answer: (b) It does not release any locks. The studentId is only a reference variable as it is not declared using the new operator. Abstraction can be achieved with either abstract classes or interfaces (which you will learn more about in the next chapter).. E. Below are few Software Engineering MCQ test that checks your basic knowledge of Software Engineering.This Software Engineering Test contains around 20 questions of multiple choice with 4 options.You have to select the right answer to a question. Explanation: Abstraction is the concept of defining real world objects in terms of classes or interfaces. The Javadoc command line syntax is,
According to the string "Complete," "o" is at position 1, and "e" is at the position 7. Compilation is the process of converting the code into a language that is – a. The getClass() method of the Object class returns the runtime class of this object. public abstract void method() {}. It is a part of the Java Platform Debugger Architecture (JPDA) that helps in the inspections and debugging of a local or remote Java Virtual Machine (JVM). This set of Object Oriented Programming (OOPs) Multiple Choice Questions & Answers (MCQs) focuses on “Abstraction”. As per dictionary, abstraction is the quality of dealing with ideas rather than events. Thread-safe means that the methods and objects of a class are accessible by multiple threads at the same time. Data Types and Variables Declaration and Access Control Array Strings Operators Constructors and Methods Flow Control Overriding and Overloading Interfaces and Abstract Classes Inheritence Exceptions Threads Input Output . 2) Which of the following is not a Java features? It is because the wait() method must be used inside a synchronized block or try-catch block unless it will throw an exception, as shown above. abstraction is an oops concept. It contains well written, well thought and well explained computer science and programming articles, quizzes and practice/competitive programming/company interview Questions. By covering all the topics of the Java, we have arranged the Java Online Test on this page. But on dividing an integer by zero, it throws a runtime exception, i.e., java.lang.ArithmeticException. The major use of abstract classes and methods is to achieve abstraction in Java. I suggest you guys try these code snippets in eclipse IDE and understand how the program works. To synchronize the HashMap class explicitly, we should use the Collections.synchronizedMap(hashMap) method that returns a thread-safe map object. T his collection of Java Multiple Choice Questions and Answers (MCQs): Quizzes & Practice Tests with Answer focuses on “Java OOPs”.. 1. Which of the following sub-classes are included in object class in Java. Java is not robust. Please mail your requirement at hr@javatpoint.com. The rt.jar is the mandatory jar file for every core java application as it contains all the core classes. The intern() and toString() methods are of String class. The character encoding can be either a default encoding dependent on the system or encoding that is explicitly defined. The anonymous objects do not have any names. Explanation: In the above code, we have not defined the variable Y. Answer: (b) Default encoding of the host platform. 1. public void abstract Method(); D. Answer: (d) Static block, instance block, constructor, and method. Use abstraction to improve code re-usability and share the methods/variables between multiple related classes. i) Font ii) Frame iii) Float iv) File A) i and ii only B) ii and iii only C) iii and iv only D) i and iv only. Software Design MCQs. The major use of abstract classes and methods is to achieve abstraction in Java. Which of the following declares an abstract method in an abstract Java class? quiz which has been attempted 555 times by avid quiz takers. advertisement. Hence, the correct answer is the option (b). 2. Java is dynamic, architecture-neutral, and object-oriented programming language. A Graphics class is allow an application to draw onto components that are realized on various devices, as well as onto off-screen images. Whereas, the second import statement only imports the Object class of the java.lang package. An abstract method is a method which cannot be inherited. This is the reason why Green Team (Java Team members) has not introduced pointers in Java. 1 and 2, B. Both studentName and stud_class are reference variables as well as objects. MCQ 6: Java programs are. Explanation: An interface with no methods and fields is known as the marker interface. Hence, an ArrayList with the default capacity can hold ten (10) values. 1. Which one of … class A { abstract void unfinished() { } }, B. We have more than 500 (Java MCQ (Multiple Choice Questions) Quiz) Java questions and answers.Which includes at least 100 Java topics. www.gtu-mcq.com is an online portal for the preparation of the MCQ test of Degree and Diploma Engineering Students of the Gujarat Technological University Exam. : d. An abstract method is a method in the child class that overrids a … This Encapsulation in OOP online test is useful for beginners, freshers, experienced programmers, lecturers preparing for GATE, job interview, university, semester exams, certification etc. B. One is a byte stream, and the other is the character stream. The abstract keyword is a non-access modifier, used for classes and methods: . Both Statement are correct. So, the values of i will not be printed, and the above exception is thrown. If you have to crack Java very well, or take online test, or prepare for a Java interview, or do the certification, then you practice Java question and answer here, surely you can in a few months Be prepared to learn and assimilate Java on a large scale. Multiple choice questions on Object Oriented Programming topic OOPs Concept and Features. Previous Page. We can be achieved abstraction in java by using abstract class and interface. The keywords public and abstract cannot be used together. The Runnable, Readable, and Result interface are not marker interface as they contain some methods or fields. Explanation: According to the class hierarchy of Java Swing, the Applet class is the direct subclass of the Panel class. programs that are compiled to the Java bytecode. A class 'SubClass' inherits the abstract class and has a method named 'a_method' which prints "This is abstract method". Contains a lot of questions to practice and to improve your Knowledge skills in Java for exam preparation. And the rest three options are false about the anonymous inner classes as it can have both methods and objects. In Java, main is the method that is the entry point of any program, and the System is a class. Therefore, for all odd numbers till 15 (1, 3, 5, 7, 9, 11, 13, 15), it will print (***), and for all even numbers till 14 (2, 4, 6, 8, 10, 12, 14) it will print (+++++). a. In chained exceptions, the debugging information is not discarded. Answer: (a) It returns the existing string from the memory. A class which contains the abstract keyword in its declaration is known as abstract class. Java Abstract Class MCQ Questions This section focuses on the "Abstract class" in Java programming language. Now, evaluate the statement by putting the values of x, y, and z. Which keyword is used to define interfaces in Java? Hence, an asterisk (***) will be printed eight times, and plus (+++++) will be printed seven times. D. None of the above. We can also say that, when an object is initialized but is not assigned to any reference variable, it is called an anonymous object. The other three are inheritance, polymorphism, and abstraction. Three reference variables and three objects are created. Explanation: From the above statements, the new List(3, true) is the correct answer; this is because of the constructor type. Then the code would execute. The package keyword is used to create a new package. The JVM (Java Virtual Machine) enables a computer to run Java or other language (kotlin, groovy, Scala, etc.) JavaTpoint offers too many high quality services. Encapsulation in Java is a mechanism for wrapping the data (variables) and code acting on the data (methods) together as a single unit. Using final with a class makes the class constant, and we cannot extend a final class. One or more additional 'u' characters that are optional. An object without having any name but having a reference. A subclass can override a concrete method in a superclass to declare it abstract. Your welcome to this quick Java MCQ Quiz. The RuntimeException, IOException, and VirtualMachineError classes are the subclasses of the Exception and Error classes. This set of Object Oriented Programming (OOPs) Multiple Choice Questions & Answers (MCQs) focuses on “Abstraction”. This situation is known as race condition. Explanation: In tight coupling, a group of classes and objects are highly dependent on each other. Also explore over 178 similar quizzes in this category. Java - Abstraction. Java programs are A) Faster than others B) Platform independent C) Not reusable D) Not scalable. 1. 2 and 3, No explanation is given for this question. It contains an abstract method named num() that is not defined properly. Attempt and Practice with this huge collection of Complete Java Programming MCQ questions and answers quiz. Explanation: In Java, multiple threads can be executed at the same time. 1. The Java programs executed by the JVM that makes the code portable and secure. This part of Java MCQ contains Java multiple choice questions with their answers. 36) Given that Student is a class, how many reference variables and objects are created by the following code? For more information Refer:Abstract Classes in Java Option (D) is correct. That enables the user to implement more complex logic on top of the provided abstraction without understanding or even thinking about all the hidden complexity. Hence, the correct answer is an option (d). 50) What is the default encoding for an OutputStreamWriter? In the option b), to make a String valid char literal, we should add prefix "\u" in the string. In other words, an empty interface (contains nothing) is known as the marker interface. The Graphics class is in java is the abstract base class for all graphics contexts. Ex: A car is viewed as a car rather than its individual components. Which of the following statements regarding abstract classes are true? Class School must be defined abstract. 30 Java Practice Coding Questions On Abstract Classes pramodbablad November 18, 2015 17 1) Below class ABC doesn’t have even a single abstract method, but it … I want to have an abstract class that has an abstract method, say abstract void compare(). ... Constructor Interview Question in Java Abstraction Interview Question in Java. Explanation: According to the class hierarchy of Throwable class, the Error and Exception classes are the direct subclasses of the Throwable class, as shown below. public void method() {}, E. These questions may ask in interviews or similar questions may appear in interviews so prepare yourself. 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