Interview Questions and Answers for 'Code' | Search Interview Question - javasearch.buggybread.com
Javasearch.buggybread.com

Search Interview Questions


 More than 3000 questions in repository.
 There are more than 900 unanswered questions.
Click here and help us by providing the answer.
 Have a video suggestion.
Click Correct / Improve and please let us know.
Label / Company      Label / Company / Text

   



Interview Questions and Answers - Order By Rating

   next 30
 Q61. Write a Program to check number of occurrences of one string within another ? Core Java
Ans. public class Class{
   public static void main(String[] args){
      String string1 = "Hello I am Jack. I live in United States. I live in california state.";

      String string2 = "I live in";

      int startIndex = 0;
      int endIndex = string1.length()-1;

      int countNoOfOccurences = 0;

      String remainingString = string1;

      while(startIndex < endIndex){
         if(remainingString.indexOf(string2) != -1){
            countNoOfOccurences++;
            startIndex = remainingString.indexOf(string2) + string2.length();
            remainingString = remainingString.substring(startIndex);
         } else {
            break;
         }
      }

      System.out.println(countNoOfOccurences);
   }
}

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

   Like         Discuss         Correct / Improve     string  code  coding     Asked in 2 Companies

 Q62. Write a program to check is a string is substring of another ?Core Java
Ans. public class Class{
   public static void main(String[] args){
      String string1 = "Hello I am Jack. I live in United States. I live in california state.";

      String string2 = "I live in";

      if(string1.indexOf(string2) >= -1){
         System.out.println("string2 is sub string of string1");
      } else {
         System.out.println("string2 is not sub string of string1");
      }
   }
}

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

   Like         Discuss         Correct / Improve     string  coding  code

 Q63. Write a class / program that takes few numbers from the input and then output the average ?Core Java
Ans. public class Class{
   public static void main(String[] args){
      List<Integer> collector = new ArrayList();

      Scanner scanner = new Scanner(System.in);
      int x = scanner.nextInt();
      while(x != 0){
         collector.add(x);
         x = scanner.nextInt();
      }
      System.out.println(collector.stream().collect(Collectors.averagingInt(p->((Integer)p))));
   }
}

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

   Like         Discuss         Correct / Improve     coding  code  collector  streams  Collectors.average     Asked in 1 Companies

 Q64. What will be the output of following code ?

Base Interface

public interface BaseInterface {
   int i = 4;
}

Derived Interfaces

public interface DerivedInterface1 extends BaseInterface{
   int i = 5;
}

public interface DerivedInterface2 extends BaseInterface{
   int i=6;
}

Implementing Class

public class Class implements DerivedInterface1,DerivedInterface2 {
int i=10;   

public static void main(String[] args){
      System.out.println(new Class().i);
   }
}

What will be the output upon executing main and Why ?		Core Java
Ans. 10

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

   Like         Discuss         Correct / Improve     interfaces  coding  code      intermediate

 Q65. What will be the output of following code ?

Base Interface

public interface BaseInterface {
   int i = 4;
}

Derived Interfaces

public interface DerivedInterface1 extends BaseInterface{
   int i = 5;
}

public interface DerivedInterface2 extends BaseInterface{
   int i=6;
}

Implementing Class

public class Class implements DerivedInterface1,DerivedInterface2 {
   public static void main(String[] args){
      System.out.println(BaseInterface.i);
   }
}

What will be the output upon executing main and Why ?		Core Java
Ans. It will print 4 because member elements of an interface are implicitly static and hence the concept of overriding doesn't work.


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

   Like         Discuss         Correct / Improve     interfaces  coding  code  extending interfaces  diamond interfaces     Asked in 1 Companies      intermediate

Usually asked to entry level software developers.
  Q66. Write a program to swap two variables without using thirdCore Java
Ans. public static void main(String[] args) {
   int num1 = 1;   
   int num2 = 2;
   num1 = num1^num2;
   num2 = num1^num2;
   num1 = num1^num2;
   System.out.print("num1 = " + num1 +", num2 = "+num2);
}

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

   Like         Discuss         Correct / Improve     code  coding     Asked in 37 Companies      basic        frequent

 Q67. Write an algorithm / Java Program to show duplicates in an array of n elements?Algorithm
Ans. int duplicateArray[] = { 1, 2, 2, 3, 4, 5, 6, 8, 9}
Set unique = new HashSet();
for (int i = 0; i < duplicateArray.length; i) {
if (unique.contains(duplicateArray[i])) {
System.out.println(duplicateArray[i]);
} else {
unique.add(duplicateArray[i]);
}
}

Complexity O(n) = nHashSet contains and add has O(n) = 1

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

   Like         Discuss         Correct / Improve     coding  code     Asked in 2 Companies

 Q68. Do you feel that its useless to define hashCode method for a class ?Core Java
Ans. Yes its useless if we are not going to use its objects within Hash collection, For example - HashSet , HashMap. HashCode is used internally by these collections for Search.

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

   Like         Discuss         Correct / Improve     hashcode  hash collections  search

 Q69. Trim a string without using String library methodCore Java
 This question was recently asked at 'Ariba'.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.string  trim a string     Asked in 1 Companies

Frequently asked in high end product companies.
 Q70. Write code for LRU CacheCore Java
Ans. https://www.geeksforgeeks.org/lru-cache-implementation/

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

   Like         Discuss         Correct / Improve     cache  LRU cache  coding  code     Asked in 10 Companies      intermediate

 Q71. How is hashcode calculated in java ?

or

What are the rules for hashcode calculation ?		Core Java
Ans. General contract of hashCode is:

1.Whenever it is invoked on the same object more than once during an execution of a Java application, the hashCode method must consistently return the same integer,

2.If two objects are equal according to the equals(Object) method, then calling the hashCode method on each of the two objects must produce the same integer result.

3.It is not required that if two objects are unequal according to the equals(java.lang.Object) method, then calling the hashCode method on each of the two objects must produce distinct integer results.

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

   Like         Discuss         Correct / Improve     hashcode     Asked in 1 Companies      expert

 Q72. What do you look for when you do code review ?Core Java
Ans. Modularity - First sign of good code is whether it has been segregated into methods and classes appropriately. I dont mind it in excess because I believe that is forward looking strategy as applications tends to expand and eventually become hard to read.

Self Explanatory - Variables and methods should be named in a way that the code should be self explanatory even without comments. Use of Constant variables to explain use of literal.

Proper Code Reuse - If there is anything being reused , it should be moved to parent classes / methods.

Proper composition calls - Composed hierarchy should not be access in just single line. One or two levels is ok but having multiple levels make it hard to read and debug.

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

   Like         Discuss         Correct / Improve     code review  clean code     Asked in 1 Companies      intermediate        frequent

 Q73. Provide an implementation for Producer / Consumer using threads.Core Java
Ans. https://www.tutorialspoint.com/javaexamples/thread_procon.htm

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

   Like         Discuss         Correct / Improve     coding  code     Asked in 1 Companies

 Q74. Explain some of the http status codes you know ?Java EE
Ans. 500 is Internal Server Error

404 is resource not found

400 is Bad Request

403 is Forbidden

401 is Unauthorized

200 is OK

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

   Like         Discuss         Correct / Improve     http  http status codes     Asked in 2 Companies        frequent

 Q75. Write a Program to print the positive and negative numbers separetlyCore Java
Ans. int[] arr = {1,-1,2,-3,3,-4,4,5,6,-5,-6,-7,-8,8,9,-9};
List positiveNumbers = new ArrayList<>();
List negativeNumbers = new ArrayList<>();
for(int i = 0; i < arr.length(); i ){
if(I < 0){
negativeNumbers.add(i);
} else {
positiveNumbers.add(i);
}
}

System.out.println("Positive Numbers:" + positiveNumbers);
System.out.println("Negative Numbers:" + negativeNumbers);

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

   Like         Discuss         Correct / Improve     code  program  coding     Asked in 1 Companies

 Q76. Implement the following method ?

int findMax(int[] items)
Core Java
Ans. int findMax(int[] items){
   int maxNumber = 0;
   for(int x:items){
      if(x > maxNumber){
         maxNumber = x;
      }
   }
      
   return maxNumber;
}

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

   Like         Discuss         Correct / Improve     coding  code  find max number in an array     Asked in 1 Companies

 Q77. Write a Program to add 1-100, 101-200, 201-300 in different threads and then sum the numbers ?Core Java
Ans. public class TotalUsingThreads extends Thread{
   
   private static List<TotalUsingThreads> collector = new ArrayList<TotalUsingThreads>();
   
   private int startFrom = 0;
   
   private Integer threadTotal = null;
   
   Test(int startFrom){
      this.startFrom = startFrom;
   }
   
   
   public static void main(String[] args) throws InterruptedException{
      int totalSum = 0;
      
      // Create all the threads and set the count starting point for all of them
      for(int count=0;count<10;count++){
         TotalUsingThreads newThread = new TotalUsingThreads(count*100);
         newThread.start();
         collector.add(newThread);
      }
      
      boolean allCollected = false;
      
      
      // Make sure that all thread totals are collected and all threads have completed their tasks
      while(!allCollected){
         for(int count=0;count<10;count++){
            if(collector.get(count).threadTotal == null){
               Thread.sleep(100);
               break;
            }
         }
         allCollected = true;
      }
      
      // sum totals of all threads
      for(int count=0;count<10;count++){
         totalSum += collector.get(count).threadTotal;
      }
      
      System.out.println(totalSum);
      
      
   }
   
   public void run(){
      threadTotal = 0;
      for(int count=startFrom;count<startFrom+100;count++){
       threadTotal += count;   
      }
   }
}

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

   Like         Discuss         Correct / Improve     coding  code  threads  multithreading     Asked in 1 Companies

 Q78. How would you count the number of words in a string consisting of uneven number of spaces between words( not dictionary words)? With and without library functions.Core Java
Ans. package com.string;

import java.util.Scanner;

public class String13 {
public static void main(String[] args) {
System.out.println("Enter Sentence");
Scanner sc=new Scanner(System.in);
String sentence=sc.nextLine();
String[] words=sentence.split(" ");
int count=0;
for (String string : words) {
string.trim();
if(!string.equals("")){
count++;
System.out.println(string " " count);
}
}
}
}

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

   Like         Discuss         Correct / Improve     code  coding     Asked in 1 Companies

 Q79. Write a Java Program to check Armstrong Number ?Core Java
Ans. http://www.programmingsimplified.com/java/source-code/java-program-armstrong-number

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

   Like         Discuss         Correct / Improve     program  code  coding  armstrong number     Asked in 1 Companies

 Q80. What does the web status code 404,500 and 200 mean ?Java EE
Ans. 404 means the resource is not found on the server.The resource might not be deployed correctly.

500 means internal server error which means that resource was located but then it resulted in some exception or error.

200 means Ok.

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

   Like         Discuss         Correct / Improve     web status code     Asked in 1 Companies
Try 1 Question(s) Test

 Q81. What is wrong with the following if statement ?

if(x==y || x.equals(y) {
}		Core Java
Ans. if x==y turns out to be true x.equals(y) will be true too. If x.equals(y) could be true even if x==y is true or not.

So the only possible outcomes are

1 || 1 = 1
0 || 1 = 1
0 || 0 = 0

i.e the outcome of x.equals(y)

check for x==y is not required in this if statement.

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

   Like         Discuss         Correct / Improve     if statement  control statements  == and equals  ==  .equals   code optimization
Try 1 Question(s) Test

 Q82. What is wrong with the following if statement ?

if(x==y && x.equals(y) {
}		Core Java
Ans. x==y means that both references have same type and are pointing to same memory location and hence would always mean that they have same value.

x.equals(y) is not required in this case.

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

   Like         Discuss         Correct / Improve     if statement  control statements  == and equals  ==  .equals   code optimization
Try 2 Question(s) Test

 Q83. Is this code legal in Java ?

public class BuggyBread {
{
System.out.println("HelloWorld.");
}
}
Ans. Yes, It's an instance initialization block.

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

   Like         Discuss         Correct / Improve     code  instance initialization block
Try 1 Question(s) Test

 Q84. What is the problem with following code ?

public static void main(String[] args) {
int x = 5;
return x*2;

int y = 10;
return y*2;

}
Ans. There are many problems with the code

1. The method returns void and hence we cannot return any integer value.

2. We cannot return more than one value from a method.

3. The code after 1st Return statement is unreachable.

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

   Like         Discuss         Correct / Improve     coding  code

 Q85. What are the steps to create a branch in SVN ?
Ans. If the branch is to be created from Trunk and we are using Eclipse.

Go to the Trunk Copy of the Project

Right Click the project and then Click Branch/Tag

In the Create Branch / Tag Dialog, Add the Destination Branch Url

Check whether we want to make copy from the Head Revision or some specific revision Number

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

   Like         Discuss         Correct / Improve     scm  source code management  svn  version control  code repository  svn branch

 Q86. Is it advisable to just hold checking in your changes to trunk if there is another release planned in between ?
Ans. If it's just smaller change, and single person is working, then this approach is fine. Otherwise there are risk on loosing it on your machine. Moreover , If there are multiple people working , it makes it hard to share code. It's better to create a separate branch and then merge it later to trunk.

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

   Like         Discuss         Correct / Improve     scm  source code management  svn  version control  code repository  svn trunk

 Q87. How do you manage source code in repository if you have multiple releases lined up and different teams are working on it? Tools
Ans. We creates separate branches for each project if development work is going on parallel and they are to be released at different times. Once the first release is done, we merge the branch changes into trunk. If they all have to go at one time, we usually would merge everything in the trunk itself.

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

   Like         Discuss         Correct / Improve     scm  source code management  svn  version control  code repository  svn branch     Asked in 1 Companies

This question can be asked in different variants like performace improvement of an application, improving performance for DB communication etc.
 Q88. What are the ways in which execution time of the code can be improved ?Solution
Ans. This depends on entirely upon the code type. For example

1.If its just logic, we can try it to short circuit or put the if / switch case with maximum probability in the beginning.

2. Can use faster data structures, for eg - random retrieval instead of sequence / iterator

3. Working with primitive types or even bytes instead of Objects, even though it may result in marginal improvement.

4. If its service call, then service call with bulk load can help

5. If DB Operation, then with use of Indices , Views or using ORM , cache etc.


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

   Like         Discuss         Correct / Improve     performance improvement  code optimization     Asked in 1 Companies

Very frequently asked. Among first few questions in almost all interviews. Among Top 5 frequently asked questions. Frequently asked in Indian service companies (HCL,TCS,Infosys,Capgemini etc based on multiple feedback ) and Epam Systems
  Q89. Difference between == and .equals() ?Core Java
Ans. "equals" is the method of object class which is supposed to be overridden to check object equality, whereas "==" operator evaluate to see if the object handlers on the left and right are pointing to the same object in memory.

x.equals(y) means the references x and y are holding objects that are equal. x==y means that the references x and y have same object.

Sample code:

String x = new String("str");
String y = new String("str");

System.out.println(x == y); // prints false
System.out.println(x.equals(y)); // prints true

  Sample Code for equals

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

   Like         Discuss         Correct / Improve     java   string comparison   string   object class   ==    equals   object equality  operator   == vs equals   equals vs ==     Asked in 294 Companies      basic        frequent
Try 6 Question(s) Test

Very frequently asked. Favorite question in Walk in Drive of many Indian service companies.
  Q90. What is a final method ?Core Java
Ans. Its a method which cannot be overridden. Compiler throws an error if we try to override a method which has been declared final in the parent class.

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

   Like         Discuss         Correct / Improve     java   oops   final   final method     Asked in 30 Companies      basic        frequent
Try 1 Question(s) Test

previous 30   next 30

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

Any input from you will be highly appreciated and It will unlock the application for 10 more requests.

Company Name:
Questions Asked: