Interview Question and Answers | Search Coding Interview Questions

Interview Questions and Answers - Order By Rating

Q2821. what is covariant return type?

Ans. co-variant return type states that return type of overriding method can be subtype of the return type declared in method of superclass. it has been introduced since jdk 1.5

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve java oops inheritence overriding covariant return type jdk5 advanced Asked in 3 Companies expert}

Q2822. How compiler handles the exceptions in overriding ?

Core Java

Ans. 1)The overriding methods can throw any runtime Exception , here in the case of runtime exception overriding method (subclass method) should not worry about exception being thrown by superclass method.

2)If superclass method does not throw any exception then while overriding, the subclass method can not throw any new checked exception but it can throw any runtime exception

3) Different exceptions in java follow some hierarchy tree(inheritance). In this case , if superclass method throws any checked exception , then while overriding the method in subclass we can not throw any new checked exception or any checked exception which are higher in hierarchy than the exception thrown in superclass method

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve java overriding exceptions inheritence inheritance object oriented programming (oops) oops concepts oops}

Q2823. Why is Java considered Portable Language ?

Core Java

Ans. Java is a portable-language because without any modification we can use Java byte-code in any platform(which supports Java). So this byte-code is portable and we can use in any other major platforms.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve java bytecode jvm compiler portable features of java basic interview question}

Q2824. Tell something about history of Java ?

Core Java

Ans. Java was initially found in 1991 by James Gosling, Sun Micro Systems. At first it was called as "Oak". In 1995 then it was later renamed to "Java". java is a originally a platform independent language. Currently Oracle, America owns Java.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve java history of java}

Q2825. How to find if JVM is 32 or 64 bit from Java program. ?

Core Java

Ans. You can find JVM - 32 bit or 64 bit by using System.getProperty() from Java program.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve java jvm 32 jvm 64 jvm}

Q2826. Does every class needs to have one non parameterized constructor ?

Core Java

Ans. No. Every Class only needs to have one constructor - With parameters or without parameters. Compiler provides a default non parameterized constructor if no constructors is defined.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve java oops constructor default constructor yes no intermediate}

Try 3 Question(s) Test

Q2827. Difference between throw and throws ?

Core Java

Ans. throw is used to explicitly throw an exception especially custom exceptions, whereas throws is used to declare that the method can throw an exception.

We cannot throw multiple exceptions using throw statement but we can declare that a method can throw multiple exceptions using throws and comma separator.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve java exceptions exception handling throw throws difference between basic interview question basic frequent}

Try 1 Question(s) Test

Q2828. Can we use "this" within static method ? Why ?

Core Java

Ans. No. Even though "this" would mean a reference to current object id the method gets called using object reference but "this" would mean an ambiguity if the same static method gets called using Class name.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve java oops static this keyword this yes no why questions intermediate}

Q2829. Similarity and Difference between static block and static method ?

Core Java

Ans. Both belong to the class as a whole and not to the individual objects. Static methods are explicitly called for execution whereas Static block gets executed when the Class gets loaded by the JVM.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve java oops static static method static block difference between similarity basic frequent}

Try 1 Question(s) Test

Q2830. What are the platforms supported by Java Programming Language?

Core Java

Ans. Java runs on a variety of platforms, such as Windows, Mac OS, and the various versions of UNIX/Linux like HP-Unix, Sun Solaris, Redhat Linux, Ubuntu, CentOS, etc

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve java jvm platforms}

Q2831. How Java provide high Performance ?

Core Java

Ans. Java uses Just-In-Time compiler to enable high performance. Just-In-Time compiler is a program that turns Java bytecode into instructions that can be sent directly to the processor.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve java compiler jvm bytecode justintime compiler architecture}

Q2832. What is IDE ? List few Java IDE ?

Tool

Ans. IDE stands of Integrated Development Environment. Few Java IDE's are WSAD ( Websphhere Application Developer ) , RAD ( Rational Application Developer ) , Eclipse and Netbeans.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve java ide ide java development wsad rad eclipse netbeans}

Q2833. What is an Object ?

Core Java

Ans. Object is a run time entity whose state is stored in fields and behavior is shown via methods. Methods operate on an object's internal state and serve as the primary mechanism for object-to-object communication.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve java oops objects basic interview question Asked in 1 Companies basic frequent}

Q2834. What is a Class ?

Core Java

Ans. A class is a blue print or Mold using which individual objects are created. A class can contain fields and methods to describe the behavior of an object.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve java oops class basic interview question Asked in 1 Companies basic frequent}

Q2835. According to Java Operator precedence, which operator is considered to be with highest precedence?

Core Java

Ans. Postfix operators i.e () [] . is at the highest precedence.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve java operators operator precedence Asked in 2 Companies}

Q2836. What data type Variable can be used in a switch statement ?

Core Java

Ans. Variables used in a switch statement can only be a byte, short, int, or char ( and String with Java 7 and above )

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve java switch variable data type basic rare}

Q2837. What are the sub classes of Exception class?

Core Java

Ans. The Exception class has two main subclasses : IOException class and RuntimeException Class.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve java exceptions exception class ioexception runtimeexception}

Q2838. How finally used under Exception Handling?

Core Java

Ans. The finally keyword is used to create a block of code that follows a try block. A finally block of code always executes, whether or not an exception has occurred.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve java exceptions exception handling try finally basic interview question Asked in 1 Companies}

Try 1 Question(s) Test

Q2839. What things should be kept in mind while creating your own exceptions in Java?

Core Java

Ans. All exceptions must be a child of Throwable.

If you want to write a checked exception that is automatically enforced by the Handle or Declare Rule, you need to extend the Exception class.

You want to write a runtime exception, you need to extend the RuntimeException class.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve java exceptions exception handling user defined exceptions throwable architecture library development technical architect technical lead}

Q2840. What is Comparable Interface?

Core Java

Ans. It is used to sort collections and arrays of objects using the collections.sort() and java.utils. The objects of the class implementing the Comparable interface can be ordered.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve java collections comparable interface Asked in 7 Companies intermediate frequent}

Try 1 Question(s) Test

Q2841. Explain Set Interface?

Core Java

Ans. It is a collection of element which cannot contain duplicate elements. The Set interface contains only methods inherited from Collection and adds the restriction that duplicate elements are prohibited.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve java collections set interface set}

Q2842. What is the difference between the Reader/Writer class hierarchy and the InputStream/OutputStream class hierarchy?

Core Java

Ans. The Reader/Writer class hierarchy is character-oriented, and the InputStream/OutputStream class hierarchy is byte-oriented

Sample Code for InputStream

Sample Code for OutputStream

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve java file io streams reader class writer class inputstream outputstream stream file handling}

Q2843. What are use cases?

Process

Ans. It is part of the analysis of a program and describes a situation that a program might encounter and what behavior the program should exhibit in that circumstance.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve use cases design high level design testing test driven development software system analyst project lead basic frequent}

Q2844. Which Java operator is right associative?

Core Java

Ans. The = operator is right associative.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve java operators = operator}

Q2845. What is the difference between a break statement and a continue statement?

Core Java

Ans. Break statement results in the termination of the statement to which it applies (switch, for, do, or while). A continue statement is used to end the current loop iteration and return control to the loop statement.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve java break continue loop for loop control statements loop statement while loop control statements loop statement break continue difference between basic interview question basic frequent}

Q2846. What is the purpose of the System class?

Core Java

Ans. The purpose of the System class is to provide access to system resources.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve java system io file io}

Q2847. Variable of the boolean type is automatically initialized as?

Core Java

Ans. The default value of the boolean type is false.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve java data type boolean initialization default object construction default constructor default value}

Q2848. Can try statements be nested?

Core Java

Ans. Yes

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve java exceptions try yes no basic}

Q2849. What will happen if static modifier is removed from the signature of the main method?

Ans. Program throws "NoSuchMethodError" error at runtime .

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve java main method main static static method nosuchmethoderror}

Q2850. What is the Locale class?

Ans. The Locale class is used to tailor program output to the conventions of a particular geographic, political, or cultural region

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve java locale internationalization intermediate rare}

Search Interview Questions

Help us and Others Improve. Please let us know the questions asked in any of your previous interview.