Interview Questions and Answers - Order By Newest Q1651. Write a Program to check if the entered number is a Duck Number ( Number having 0 in it ) ? Core Java
This question is still unanswered. Can you please provide an answer. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  code  coding  duck number Q1652. What will the following code print ?
int x[] = new int[5];
x[0] = 1;
x[1] = 2;
for(int count=0;count<x.length;count++){
System.out.println(x[count]);
} Core Java
Ans. 1
2
0
0
0
As arrays are not dynamically expanded , we have declared the array for size 10. As we have only initialized only 2 values , it will print rest as their default values. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  arrays Q1653. What will the following code print
int x[] = new int[5];
x[0] = 1;
x[1] = 2;
for(int count=0;count<=x.length;count++){
System.out.println(x[count]);
} Core Java
Ans. 1
2
0
0
0
ArrayIndexOutOfBoundException: 5
As array index starts with 0 and ends with the index of (size - 1), the index 5 is inaccessible for the array and hence will throw the exception. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  arrays Q1654. How to use spring boot to configure different datasources ? Spring Boot
Ans. https://github.com/jahe/spring-boot-multiple-datasources Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  Spring Boot Asked in 1 Companies Q1655. what are different pointer operators used ? Core Java
This question was recently asked at 'Huawei Technologies'.This question is still unanswered. Can you please provide an answer. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve   Asked in 1 Companies This question is still unanswered. Can you please provide an answer. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve   Q1657. Which java features makes java different from other languages ? Core Java
This question is still unanswered. Can you please provide an answer. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve   Q1658. Why cant we start an identifier with a number in Java? Core Java
This question is still unanswered. Can you please provide an answer. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve   Q1659. What is the default data type of Serialized methods?' Core Java
This question was recently asked at 'Intime Tec'.This question is still unanswered. Can you please provide an answer. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve   Asked in 1 Companies Q1660. Do we have a method to reverse a string in String class ? Core Java
Ans. No but we have it in StringBuilder. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  String  StringBuilder  Reverse a string Q1661. How can we convert char into a String ? Core Java
Ans. We can use StringBuilder. StringBuilder accepts char as the argument for it's constructor.
new StringBuilder('').toString(); Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  convert char to String  char  String Q1662. How can we check if a particular character is upper case in Java ? Core Java
Ans. 1. We can compare the ascii value of the character. Ascii for Capital case character is from 65 to 90.
2. We can compare to see if lowerCase of the character is not equal to character itself.
For example -
if character is 'a' the following code
new StringBuilder(char).toString().toLowerCase().equals(new StringBuilder(char)
will return true and hence char is lower case
if character is 'A' the following code
new StringBuilder(char).toString().toLowerCase().equals(new StringBuilder(char)
will return false and hence char is upper case Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  check upper case character  character Q1663. How different is it when final applied to variables and object references ? Core Java
Ans. final when assigned to object references doesn't make them immutable. It means that the references cannot be de-referenced.
final when applied to variables means that the value cannot be changed. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  final keyword  final variable Q1664. Why the following code produced this output ?
int x = 5;
int y = x;
y = 10;
System.out.println(x); // prints 5 and not 10 Core Java
Ans. Because when we say y = x, the value of x is copied to another memory location and then y points to that new memory location.
Unlike object references that once assigned point to same object in memory, value is copied in case of variable assignment. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  variable assignment Q1665. In which memory segment - heap or stack, the following stored by JVM
1. static members
2. objects
3. object references
4. local or method variables
Core Java
Ans. static members are stored in method area of heap
objects are stored on heap
object references are stored on stack
local or method variables are stored on stack Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  jvm  memory management  stack  heap Q1666. Write a Program to implement stack using LinkedList. Data Structure
This question is still unanswered. Can you please provide an answer. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  Data Structure Q1667. Describe how you could use a single array to implement three stacks Algorithm
This question is still unanswered. Can you please provide an answer. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  Data Structure Q1668. How would you design a stack which, in addition to push and pop, also has a function min which returns the minimum element? Push, pop and min should all operate in O(1) time Algorithm
This question is still unanswered. Can you please provide an answer. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  Data Stricture   Big O Notation  time complexity Q1669. Write a program to sort a stack in ascending order You should not make any assumptions about how the stack is implemented The following are the only functions that should be used to write this program: push | pop | peek | isEmpty Algorithm
This question is still unanswered. Can you please provide an answer. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  Data Structures Q1670. How can we convert String into Char array and vice versa ? Core Java
Ans. There is a method toCharArray() within String class that can be used to convert string to char array.
string.toCharArray();
String class has an argument constructor that takes a char array and create a string
new String(charArray); Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  string  char array Q1671. How can we convert a character or a character array into a String ? Core Java
Ans. String has an argument constructor that take char array as argument and creates a string.
There is no constructor available with String that takes in a character and creates a String. We can use StringBuilder which has a char argument constructor. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  character  char  char array  String  char to String  char array to StringAns. Generics are a facility of generic programming that were added to the Java programming language in 2004 within J2SE5.0. They allow "a type or method to operate on objects of various types while providing compile-time type safety. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  generics Asked in 7 Companies Q1673. What are the uses of Abstraction ? Core Java
Ans. Loose Coupling
Facilitates designing complex applications by making them modular. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  oops concepts  abstraction Asked in 1 Companies Q1674. How can we track of all objects created in an application ? Design
Ans. We can store the references in a collection by adding to those objects in the collection. We can create a class "ObjectRegistry" with a collection or multiple collections with a search algorithm to look for the already collected objects. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  objects Q1675. Why is JVM called Virtual machine ? Core Java
This question is still unanswered. Can you please provide an answer. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  jvm Q1676. Lets say we have a set "set1" with objects of Class A, Class has a non static string called element1, Write a code ( using lambda expression ) to see if there is any object in the set with element1 = "Hello". Core Java
Ans. set1.stream().filter(p->p.element1.equals("Hello")).findAny().isPreent();
or
set1.stream().map(A::getElement1).anyMatch("Hello"::equals) Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  lambda expressions  java 8  java8  java 8 filter  findAny() Q1677. Which of the OOP's features facilitate dependency injection ? Design
Ans. Inheritance , Runtime Polymorphism and Composition. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  dependency injection  inversion of control  ioc  oops  oops features Q1678. Is Runtime Polymorphism possible without Inheritance ? Core Java
Ans. Yes, Runtime Polymprohism requires either Class inheritance or Interface implementation. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  runtime polymorphism  object oriented programming (oops)  oops concepts  method overriding  inheritance  object oriented programming (oops)  oops concepts Q1679. Is dependency injection possible if we don't have inheritance / Composition ? Design
Ans. Without composition - No, as it's the core of dependency injection.
With Inheritance - Yes, through interface implementation. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  dependency injection  inversion of control  ioc Q1680. Why is Java such an important Programming language ? Core Java
Ans. Because of following features
Object Oriented and hence helps build maintainable and easily enhanceable code.
Platform Independence and hence can be executed anywhere
Fast due to JIT compiler Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve