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final keyword in java is used with mcq

Final variables can be declare with static keyword in java and treated as constant. The final keyword can be applied with the variables, a final variable that have no value it is called blank final variable or uninitialized final variable. 11 + 5 - 5 + 10 + 3 = 24. The CallableStatement can return either a single ResultSet object or multiple ResultSet objects. Writing code in comment? Explanation: In Java, whenever we divide any number (double, float, and long except integer) by zero, it results in infinity. java mcqs online test. The wait() method is used to make a thread to wait until another thread invokes the notify() or notifyAll() methods for an object. Explanation: In Java, Unicode characters can be used in string literals, comments, and commands, and are expressed by Unicode Escape Sequences. Using final with a class makes the class constant, and we cannot extend a final class. Static keyword in java with examples. Posted date: They are reserved names that cannot be used as variables. The option b, c, and d, are not valid because: 8) What is the return type of the hashCode() method in the Object class? Hence, the correct answer is an option (c). One of the keywords in Java is the ‘final’ keyword. We will help you in learning.Please leave your comments and suggestions in comment section. Explanation: A marker interface is an interface with no fields and methods. A class with final keyword is known as final class in java. Explanation: In the above code, we have declared count = 1. Final variables. Answer: (d) An object that has no reference. Tight coupling is the correct answer as it is used when the logic of one class is called by the logic of another class. Final can be: variable. Explanation: In the above code, there are three reference variables and two objects. It gives compilation error if we want to change the value of final variable: Important Note: Final variables are by default read-only. It can be initialised only in constructor. Also, this page requires javascript. acknowledge that you have read and understood our, GATE CS Original Papers and Official Keys, ISRO CS Original Papers and Official Keys, ISRO CS Syllabus for Scientist/Engineer Exam, Interview Preparation For Software Developers. The correct statement will be: Java Multiple Choice Questions And Answers 2020. Two reference variables and two objects are created. Instance block, method, static block, and constructor, Method, constructor, instance block, and static block, Static block, method, instance block, and constructor, Static block, instance block, constructor, and method. In above example, you will get compilation error with text “The blank final field count may not have been initialised” at highlighted row. Explanation: In the above code, there are two values of variable a, i.e., 10 and 60. To synchronize the HashMap class explicitly, we should use the Collections.synchronizedMap(hashMap) method that returns a thread-safe map object. 39) Which of the following is a mutable class in java? ++z +y -y +z + x++ If we assign it to a reference variable like. In other words, it is a program (tool) that reads a collection of source files into an internal form. Final method is inherited but we cannot override it; If you make a class final then you cannot extend the class; Constructor can be declared as final. It includes multiple-choice questions on keywords and variables used in java, the data type used in java, the method in a java class and the default constructor used in java along with their answers. The studentName, studentId, and stud_class are the three reference variables. The final modifier is used for finalizing the implementations of classes, methods, and variables. Explanation: The InterruptedException is thrown when a thread is waiting, sleeping, or occupied. But without assigning the value of i/9 to a variable, it would not execute, and an exception is thrown, as shown below. 28) Which of the following is a marker interface? Quiz or mock test on final keyword in Java programming language. Final can be: Important Note: The final keyword can be used with the variables and a final variable that have no value is known as blank final variable. The important features of the final keyword are: Using the final keyword with a variable makes it constant or immutable. The output of the above code is shown below: In the above code, we have created a thread "f," and when started, A will be printed. 23) Which option is false about the final keyword? The final keyword in java is used to give restriction to the user. 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. All rights reserved. If the remainder is equal to 1 on dividing the count by 2, it will print (***) else print (+++++). In other words, it is a file that contains several components, which make up a self-contained, executable, and deployable jar used to execute Java applications and deploy Java applets. When a method is overridden in the child class. The volatile keyword is not a replacement of a synchronized block or method as it does not remove the need for synchronization among the atomic actions. The transient and default are keywords in Java, but they are not used for accessing a variable by a thread from any part of the program. 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. Let us take an example to understand the use of final method. Explanation: A mutable class is a class in which changes can be made after its creation. method. The notify() method is used to raise a single thread that is waiting on the object's monitor. Explanation: For every long literal to be recognized by Java, we need to add L character at the end of the expression. The java final keyword can be used in many contexts. Answer: (a) Two bytes read/write at a time. 3) What should be the execution order, if a class has a method, static block, instance block, and constructor, as shown below? But if you do not initialise final variable, you will get compilation error as below. 41) What is meant by the classes and objects that dependents on each other? A reference variable declared final can never be reassigned to refer to a different object. You have not finished your quiz. Java final Variable. In the option c), single quotes are not present. java mcqs online test. Using which keyword we can access value of the instance variables and class variables of that class inside the method of that class itself. The quiz contains multiple choice and output of program questions for interview preparation You can not change value of final variable once initialized. We can directly use these characters only if our file system allows us, else use a Unicode escape (\u) such as "\u02tee". If you make static data member of a class a final then it will become constant that means you cannot change the value of this variable throughout the class and it has to be initialized at class level. Explanation: In the above code snippet, we have passed a string with value "Complete" and set character "i" and "d" at the index position 1 and 7, respectively. JavaTpoint offers too many high quality services. In other words, the intern() method returns a reference of the string. In chained exceptions, the debugging information is not discarded. 48) What is the result of the following program? The JDK (Java Development Kit) is a software development environment used to develop Java applications and applets. View Answer It means a method with final keyword is called final method. Java provides an effective layer of abstraction to the developers by not using pointers in Java. 9) Which of the following is a valid long literal? Explanation: The Javadoc is a tool that is used to generate API documentation in HTML format from the Java source files. By default all the data members of an interface are final and static also. IT/Software Jobs Interview Preparation Source, Rakesh Singh is a highly experienced IT professional & International Published Author…Read more. JavaTpoint offers college campus training on Core Java, Advance Java, .Net, Android, Hadoop, PHP, Web Technology and Python. Explanation: The initial or default quantity of an ArrayList is 10. Keyword final is used along with: Variables; Methods; Classes final variables: If you use a variable as a final then the value of variable is become constant. It is because of the execution order of the program. Please wait while the activity loads. IT Jobs Made Easy for Freshers – Off-Campus and On-Campus, What is Encapsulation in C# – Best Answer. Explanation: The OutputStreamWriter class translates Unicode character into bytes by using the character encoding. Mail us on hr@javatpoint.com, to get more information about given services. Check whether triangle is valid or not if three points are given, Write Interview The package keyword is used to create a new package. 4) What will be the output of the following program? The Byte stream is used to perform input or output 8-bit (equals to 1 byte) Unicode bytes whereas, the Character stream is used to read or write a 16-bit (equals to 2 bytes) Unicode character. Dec 19, 2016 Hence, there are three reference variables and two objects. But in the output, the values of a and b are 60 and 30, respectively. But a final class can extend other classes. 37) Which of the following is a valid syntax to synchronize the HashMap? The code will not execute without any specific value for Y; it results in exception, as shown below. $.post('https://java2blog.com/wp-admin/admin-ajax.php', {action: 'mts_view_count', id: '215'}); And the object of this class is a thread-safe and cryptographically insecure object. Step 1: First we create a class X and make it final class by using final keyword: Step 2: Second we create a class Y which is trying to extend final class X: Step 3: Third we create a class FinalClass: Your email address will not be published. 1. 14) Which of the following creates a List of 3 visible items and multiple selections abled? The Java programs executed by the JVM that makes the code portable and secure. What is the initial quantity of the ArrayList list? If you leave this page, your progress will be lost. It generally occurs during the execution of multi-threaded application. A final variable can be explicitly initialized only once. Whereas when we create a string using double quotes, it will check for the same value as of the string in the string constant pool. In above example, you will get compilation error with text “The final field FinalExampleMain.count cannot be assigned” at highlighted row. Explanation: If two or more threads are trying to access a common resource at the same time. This also means that you must initialize a final variable. © Copyright 2011-2018 www.javatpoint.com. 25) What do you mean by chained exceptions in Java? And the rest three options are false about the anonymous inner classes as it can have both methods and objects. How multiple inheritance in Java is achieved? The reason behind final keyword is to make entity non modifiable. When a subclass declares a variable with the same name as of the parent class variable. 17) In which process, a local variable has the same name as one of the instance variables? It restrict the user. Answer: (c) A final class cannot extend other classes. I think final definition about variables is a bit short; "In Java, when final keyword is used with a variable of primitive data types (int, float, .. etc), value of the variable cannot be changed but When final is used with non-primitive variables (Note that non-primitive variables are always references to objects in Java), the members of the referred object can be changed.

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