Advanced java aptitude questions and answers pdf
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- 60 Advanced Java Interview Questions
- Advanced Java - Interview Questions and Answers
- Java Aptitude Questions and Answers
- Java Interview Questions and Answers
Java object is an object that is provided by the execution of an application. When an application is compiled an object of that application is being made. Java application on the other hand is a program that is being written in Java and being read by the Java virtual machine. What is the purpose of garbage collection in Java, and when is it used?
60 Advanced Java Interview Questions
Explanation: The output of the Java compiler is bytecode, which leads to the security and portability of the Java code. It is a highly developed set of instructions that are designed to be executed by the Java runtime system known as Java Virtual Machine JVM. The Java programs executed by the JVM that makes the code portable and secure.
Because JVM prevents the code from generating its side effects. The Java code is portable, as the same byte code can run on any platform. Explanation: The Java language does not support pointers; some of the major reasons are listed below:. Explanation: In the above code, there are two values of variable a, i. Similarly, there are two values of variable b, i.
But in the output, the values of a and b are 60 and 30, respectively. It is because of the execution order of the program.
The execution order of the program is that the static block executes first, then instance block, and then constructor. Hence, the JVM will consider the value of a and b as 60 and 30 concerning the execution order. And the value of variables c and m is 0 as we have not assigned any value to them. Explanation: In Java, Unicode characters can be used in string literals, comments, and commands, and are expressed by Unicode Escape Sequences.
A Unicode escape sequence is made up of the following articles:. The char literals are always declared in single quotes '.
Explanation: In Java, the return type of hashCode method is an integer, as it returns a hash code value for the object. Explanation: For every long literal to be recognized by Java, we need to add L character at the end of the expression.
It can be either uppercase L or lowercase l character. However, it is recommended to use uppercase character instead of lowercase because the lowercase l character is hard to distinguish from the uppercase i character. Explanation: In Java, whenever we divide any number double, float, and long except integer by zero, it results in infinity. But on dividing an integer by zero, it throws a runtime exception, i. Now, evaluate the statement by putting the values of x, y, and z.
On calculating the final answer is 24, as shown below. In other words, it is a program tool that reads a collection of source files into an internal form. The Javadoc command line syntax is, Javadoc [options] [packagenames] [sourcefiles] [ files].
The javap tool is used to get the information of any class or interface. It is also known as a disassembler. The javaw command is identical to java that displays a window with error information, and the javah command is used to generate native method functions. Explanation: From the above statements, the new List 3, true is the correct answer; this is because of the constructor type.
To create a list of 3 visible items along with the multiple selections abled, we have to use the following constructor of the List class. List int rows, boolean multipleMode : It creates a new list initialized to display the described number of rows along with the multiple selection mode. Therefore, in the statement new List 3, true , three 3 refers to the number of rows and true enables the multiple selections. Then the code would execute. Exception in thread "main" java. The other three statements are valid and will execute.
Hence, the correct answer is the option a. Explanation: The getName method of the Class class returns the name as String of the entity class, interface represented by this Class object. It is a non-static method, and available in the java. The getClass method of the Object class returns the runtime class of this object.
The intern and toString methods are of String class. Explanation: There are following reasons for considering a variable shadowing, they are listed below:. Explanation: Anonymous inner classes are the same as the local classes except that they don't have any name. The main use of it is to override methods of classes or interfaces. And the rest three options are false about the anonymous inner classes as it can have both methods and objects.
It does not have any fixed came name. Explanation: The Random class is available in the java. An object of the Random class is used to generate a series of pseudorandom numbers. And the object of this class is a thread-safe and cryptographically insecure object. The Random class provides a variety of methods that are used to create random numbers of type integers, float, long, double, etc.
Explanation: The nameless objects are basically referred to as anonymous objects. The anonymous objects do not have any names. We can also say that, when an object is initialized but is not assigned to any reference variable, it is called an anonymous object. For example, new Employee ;. In the above code, emp is a reference variable. Therefore, the above object is not anonymous, as it is assigned to a reference variable.
Explanation: An interface with no methods and fields is known as the marker interface. In other words, an empty interface containing no fields and methods is called a marker interface. Marker interfaces are also known as the Tag interface. It is used to tell the JVM or compiler that the particular class has special behavior. Explanation: According to the class hierarchy of Java Swing, the Applet class is the direct subclass of the Panel class.
The Panel class and Window class are the child classes of the Container class, and Frame and Dialog classes are the subclasses of the Window class. Explanation: The final is a reserved keyword in Java that is used to make a variable, method, and class immutable. The important features of the final keyword are:. 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.
Explanation: In Java, an exception caused by other exceptions is known as a chained exception. Generally, the first exception causes the second exception. It helps in identifying the cause of the exception. In chained exceptions, the debugging information is not discarded.
Explanation: When a String is created using a new operator, it always created in the heap memory. 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. If it is found, returns a reference of it else create a new string in the string constant pool. Explanation: The intern method is used to return the existing strings from the database. In other words, the intern method returns a reference of the string.
For example, if the string constant pool already has a string object with the same value, the intern method will return a reference of the string from the pool. Explanation: A marker interface is an interface with no fields and methods. In other words, an empty interface contains nothing is known as the marker interface.
The Runnable, Readable, and Result interface are not marker interface as they contain some methods or fields. Explanation: In the above options, strictfp is the only reserved keyword of Java. The strictfp keyword is a modifier that restricts the floating-point calculations to assure portability and it was added in Java version 1. The objects are referring to those variables that are created using the new operator. In Java, main is the method that is the entry point of any program, and the System is a class.
Explanation: The import keyword is used to access the classes and interfaces of a particular package to the current file. In other words, it is used to import the user-defined and built-in classes and interfaces into the source file of java so that the current file can easily access the other packages by directly using its name.
For example,. The first import statement imports all the classes and interfaces of java. Whereas, the second import statement only imports the Object class of the java. The package keyword is used to create a new package. The extends keyword indicates that the new class is derived from the base or parent class using inheritance, and export is not a keyword in Java.
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. 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.
According to the string "Complete," "o" is at position 1, and "e" is at the position 7. The setChar method is used to replace the original string values with the new one. Hence, the "o" and "e" are replaced by the characters "i" and "d," respectively, which results in "Cimpletd. Explanation: The rt. It generally consists of classes like java. String, java. Object, java. Exception, etc.
Advanced Java - Interview Questions and Answers
Here Coding compiler sharing a list of 60 core java and advanced java multiple choice questions and answers for freshers and experienced. These java multiple choice interview questions asked in various java interview exams. We hope this list of java mcq questions will help you to crack your next java mcq online test. All the best for your future and happy java learning. The method setValue assigns the value of i to the instance field value. What could you write for the implementation of setValue? Java Multiple Choice Questions 23 You read the following statement in a Java program that compiles and executes.
Here Coding compiler sharing a list of 40 Java Objective Questions and Answers for freshers and experienced Java developers. All the best for your future and happy Java learning. This is an example of:. Extending two or more classes. Extending one class and implementing one or more interfaces.
Java Aptitude Questions and Answers
It's a no-brainer that Java is one of the leading programming options for bagging a lucrative job. After all, the class-based, general-purpose, object-oriented programming language is one of the most widely used programming languages in the world. So, here are top interview questions on Java and answers that will help you bag a Java job or, at the very least, enhance your learning.
Java Interview Questions and Answers
These section include questions with answers on basic theory of Java to test knowledge of fundamental concept of Java programming language. If you are going to apply for an entry-level positions in Java related job , then you are not expected to answer the tricky java interview questions , rather you should have solid understating of Java basics - the fundamental concept and feature of Java as object oriented programming language. These Java mcq sets will get you acquainted with the nature of questions you may encounter during your Java interview or competitive exams for popular programming language Java related career.
Explanation: The output of the Java compiler is bytecode, which leads to the security and portability of the Java code. It is a highly developed set of instructions that are designed to be executed by the Java runtime system known as Java Virtual Machine JVM. The Java programs executed by the JVM that makes the code portable and secure. Because JVM prevents the code from generating its side effects. The Java code is portable, as the same byte code can run on any platform. Explanation: The Java language does not support pointers; some of the major reasons are listed below:.
Here we are providing Aptitude Solutions with Programs, Examples, Multiple Choice Questions and correct answer. You will also get explanation on correct.