Find all palindrome strings in a java array.

In this article, we will see how to find all palindrome strings from an array. This is a very frequently asked questions in interview.  Also there is a question to find all palindrome number from an array.  Find few more collection interview question.  


PalindromeStrings.java

package com.javadevelopersguide.lab.basic;
/**
 * This program illustrates find all palindrome strings from array.
 *
 * @author manoj.bardhan
 *
 */
public class PalindromeStrings {
public static void main(String[] args) {
String stringArray[] = { "eye", "jdg", "javadevelopersguide", "aabaa", "hello", "pip" };
for (int i = 0; i < stringArray.length; i++) {
printOnlyPalindrom(stringArray[i]);
}
}
private static void printOnlyPalindrom(String str) {
String oldString = str;
StringBuilder builder = new StringBuilder(str);
if (builder.reverse().toString().equals(oldString)) {
System.out.println(oldString + " is a Palindrome.");
}
}
}

Output -

eye is a Palindrome String.
aabaa is a Palindrome String.
pip is a Palindrome String.

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• Producer & Consumer problem solution using BlockingQueue.
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• Top 10 groovy interview question.
• Difference between groovy and java.
• What is full stack development experience.
• 5 fundamental questions of groovy.
• Write your first java program.
• Reverse string using recursive method in java.
• Comparator Interface with Examples
• Find the smallest value from array.

Find all possible palindromes in an array

In this article, we will see how to find all palindrome from an array. This is a very basic questions in interview, the interviewer will ask the same questions in different way. So, its good to know all possible questions from palindrome. Also there is a question to find all palindrome number from a list.  Find few more collection interview question.  Today we will see how to check a number is palindrome or not. 

FindAllPalindrome.java

package com.javadevelopersguide.lab.basic;
/**
 * This program illustrates find all palindrome from array.
 *
 * @author manoj.bardhan
 *
 */
public class FindAllPalindrome {
public static void main(String[] args) {
int numberArray[] = { 120, 990, 121, 777, 808, 1280 };
for (int i = 0; i < numberArray.length; i++) {
printOnlyPalindrom(numberArray[i]);
}
}
private static void printOnlyPalindrom(int number) {
int finalNumber = 0;
int oldNumber = number;
// Repeat the loop until the number became zero.
while (number != 0) {
// Get the First Digit (i.e. 1)
int firstDigit = number % 10;
// Get the Result number.
finalNumber = (finalNumber * 10) + firstDigit;
// Now get the remaining digits , after finding the first digit
number = number / 10;
}
// Now compare the finalNumber and oldNumber both are same or not.
if (finalNumber == oldNumber)
System.out.println(finalNumber + " is a Palindrome.");
}
}

Output -

121 is a Palindrome.
777 is a Palindrome.
808 is a Palindrome.

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Find More  :-

• Java 8 use Option - avoid NullPointerException
• Producer & Consumer problem solution using BlockingQueue.
• Write your first groovy program.
• Top 10 groovy interview question.
• Difference between groovy and java.
• What is full stack development experience.
• 5 fundamental questions of groovy.
• Write your first java program.
• Reverse string using recursive method in java.
• Comparator Interface with Examples
• Find the smallest value from array.

Find the number is palindrome or not

In this article, we will see how to check if a number is palindrome or not. This is a very basic questions in interview. But, you never know about what kind of question the interviewer will ask. So, better you prepare for every certain questions. Also there is a question to find all palindrome number from a list.  Find few more collection interview question.  Today we will see how to check a number is palindrome or not. 


Palindrom.java

package com.javadevelopersguide.lab.basic;
/**
 * This program illustrates how to check a number is palindrome or not.
 *
 * @author manoj.bardhan
 *
 */
public class Palindrom {
public static void main(String[] args) {
int number = 121;
int temp = number;
int finalNumber = 0;
// Repeat the loop until the number became zero.
while (number != 0) {
// Get the First Digit (i.e. 1)
int firstDigit = number % 10;
// Get the Result number.
finalNumber = (finalNumber * 10) + firstDigit;
// Now get the remaining digits , after finding the first digit
number = number / 10;
}
// Now compare the finalNumber and number both are same or not.
if (finalNumber == temp) {
System.out.println("This number is a Palindrome.");
} else {
System.out.println("This number is not a Palindrome.");
}
}
}

Output -

This number is a Palindrome.

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Find More  :-

• Java 8 use Option - avoid NullPointerException
• Producer & Consumer problem solution using BlockingQueue.
• Write your first groovy program.
• Top 10 groovy interview question.
• Difference between groovy and java.
• What is full stack development experience.
• 5 fundamental questions of groovy.
• Write your first java program.
• Reverse string using recursive method in java.
• Comparator Interface with Examples
• Find the smallest value from array.

Find the duplicate strings in a list

In this article, we will see how to find the duplicate strings and their counts from an array or list using java.  This is one of important programming questions in technical interview. In this program we have used Map and List both, so its a kind of collections interview questions. You can find few more collection interview question.  Today we will see Find the duplicate strings in a list. 

The logic is very simple here, see the below.

• At first we need we need to create a Map to hold the key-value pair. Where key is the array element and value is the counter for number of time the array element repeats.
• Then we will iterate the array and put into the map as per the above step. If the map contains the element earlier, then we will update the value +1.
• Finally we will have the map , which holds the array elements with the counter for repentance. 
• Now, we will iterate the Map , by checking the condition where the counter is more than 1 (i.e. its duplicated or repeated).

CountDuplicate.java

package com.javadevelopersguide.lab.basic;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.Map;
import java.util.Map.Entry;
/**
 * This program illustrate how to find the number of duplicate Strings in a
 * List. Also, we can find the number of repeat for each duplicate String.
 *
 * @author manoj.bardhan
 *
 */
public class CountDuplicate {
public static void main(String[] args) {
ArrayList<String> list = new ArrayList<String>(
Arrays.asList("JDG", "AA", "AA", "JAVA", "JavaScript", "Java", "Stream", "hibernate", "Hibernate"));
System.out.println("Input List = " + list);
Map<String, Integer> map = new HashMap<String, Integer>();
for (int i = 0; i < list.size(); i++) {
if (map.isEmpty()) {
map.put(list.get(i).toUpperCase(), 1);
} else if (map.containsKey(list.get(i).toUpperCase())) {
map.put(list.get(i).toUpperCase(), map.get(list.get(i).toUpperCase()) + 1);
} else {
map.put(list.get(i).toUpperCase(), 1);
}
}
int counter = 0;
for (Entry<String, Integer> entry : map.entrySet()) {
if (entry.getValue() > 1) {
counter++;
System.out.println("String Found " + entry.getKey() + " with count " + entry.getValue());
}
}
System.out.println("Total Duplicate String - " + counter);
}
}

Output -

Input List = [JDG, AA, AA, JAVA, JavaScript, Java, Stream, hibernate, Hibernate]
String Found AA with count 2
String Found JAVA with count 2
String Found HIBERNATE with count 2
Total Duplicate String - 3

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Find More  :-

• Java 8 use Option - avoid NullPointerException
• Producer & Consumer problem solution using BlockingQueue.
• Write your first groovy program.
• Top 10 groovy interview question.
• Difference between groovy and java.
• What is full stack development experience.
• 5 fundamental questions of groovy.
• Write your first java program.
• Reverse string using recursive method in java.
• Comparator Interface with Examples
• Find the smallest value from array.

How to find duplicate elements from array in Java

In this article, we will see how to find the duplicate values from an array or list using java.  This is one of important programming questions in technical interview. Each interviewer has different approach to access the candidate. But, the logic and the approach by candidate is really matter. In this program we have used Map and List both, so its a kind of collections interview questions. You can find few more collection interview question.  Today we will see how to find the duplicate values from array. 

The logic is very simple here, see the below.

• At first we need we need to create a Map to hold the key-value pair. Where key is the array element and value is the counter for number of time the array element repeats.
• Then we will iterate the array and put into the map as per the above step. If the map contains the element earlier, then we will update the value +1.
• Finally we will have the map , which holds the array elements with the counter for repentance. 
• Now, we will iterate the Map , by checking the condition where the counter is more than 1 (i.e. its duplicated or repeated).

DuplicateFinder.java

package com.javadevelopersguide.lab.basic;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.Map;
import java.util.Map.Entry;
/**
 * This program illustrate to find the duplicate values in a List.
 *
 * @author manoj.bardhan
 *
 */
public class DuplicateFinder {
public static void main(String[] args) {
ArrayList<Integer> list = new ArrayList<Integer>(Arrays.asList(4, 3, 5, 25, 25, 25, 13, 5, 22, 4, 90));
System.out.println("List Date = " + list);
Map<Integer, Integer> map = new HashMap<Integer, Integer>();
for (int i = 0; i < list.size(); i++) {
if (map.isEmpty()) {
map.put(list.get(i), 1);
} else if (map.containsKey(list.get(i))) {
map.put(list.get(i), map.get(list.get(i)) + 1);
} else {
map.put(list.get(i), 1);
}
}
System.out.println("\nDuplicate values are: ");
// Iterate the Map and display the duplicate values.
for (Entry<Integer, Integer> entry : map.entrySet()) {
if (entry.getValue() > 1) {
System.out.println(entry.getKey());
// TODO We can now put these values into any list.
}
}
}
}

Output - 

Input List Data = [4, 3, 5, 25, 25, 25, 13, 5, 22, 4, 90]
Duplicate values are:
4
5
25

Happy Learning.

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Find More  :-

• Java 8 use Option - avoid NullPointerException
• Producer & Consumer problem solution using BlockingQueue.
• Write your first groovy program.
• Top 10 groovy interview question.
• Difference between groovy and java.
• What is full stack development experience.
• 5 fundamental questions of groovy.
• Write your first java program.
• Reverse string using recursive method in java.
• Comparator Interface with Examples
• Find the smallest value from array.
• Find the duplicate Strings and counts in a List.

Find the largest number from an array using java

In this article, we will see how to find the largest number from an array using java.  This is one of basic questions in technical interviews. Earlier post we had seen how to find the smallest element from array. Now we will see how to find the largest number from integer array using java. 

The logic is very simple here, see the below.

• At first we need to assume any element as largest value. Example - 0th location.
• Then iterate over the array and compare with each element , whether its larger than the assumed larger value or not. If array element is larger then assign the array element value to assumed variable. Repeat the entire until end. 

FindLarestNumerInArray.java

package com.javadevelopersguide.lab.basic;
/**
 * This program illustrate how to find the Largest number from an array.
 *
 * @author manoj.bardhan
 *
 */
public class FindLarestNumerInArray {
// Find the largest value from an array.
public static void main(String[] args) {
int[] arr = { 200, 3, 4, 24, 33, 24, 22, 55, 90, 103, 150 };
// Assume the largest value is 0th Index
int largest = arr[0];
for (int i = 0; i < arr.length - 1; i++) {
if (arr[i] >= largest) {
largest = arr[i];
}
}
System.out.println("Largest Number is ::" + largest);
}
}

Output - 

Largest Number is ::200

Using Java 8

int largest = IntStream.of(arr).boxed().max(Comparator.naturalOrder()).get().intValue() ;

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Find More  :-

• Java 8 use Option - avoid NullPointerException
• Producer & Consumer problem solution using BlockingQueue.
• Write your first groovy program.
• Top 10 groovy interview question.
• Difference between groovy and java.
• What is full stack development experience.
• 5 fundamental questions of groovy.
• Write your first java program.
• Reverse string using recursive method in java.
• Comparator Interface with Examples
• Find the smallest value from array.
• How to find the duplicate element form list.

Find smallest number in array java

In this article, we will see how to find the smallest number from an array using java.  This is one of basic questions in technical interviews. Earlier post we had seen how to use stream for finding the missing number. Now we will see how to find the smallest number from integer array using java. 


The logic is very simple here, see the below.

• At first we need to assume the first smallest element.
• Then iterate over the array and compare with each element , whether its smaller than the assumed value or not. If array element is smaller then assign the array element value to assumed variable. Repeat the entire until end. 

FindSmallestNumberInArray.java

package com.javadevelopersguide.lab.basic;
/**
 * This program illustrate how to find the smallest number from an array.
 *
 * @author manoj.bardhan
 *
 */
public class FindSmallestNumberInArray {
// Find the smallest value from an array.
public static void main(String[] args) {
int[] arr = { 200, 3, 4, 24, 33, 24, 22, 55, 90, 103, 150 };
// Assigning 0th index as first smallest number to proceed the program.
int smallest = arr[0];
for (int i = 0; i < arr.length - 1; i++) {
if (arr[i] <= smallest) {
smallest = arr[i];
}
}
System.out.println("Smallest Element is - " + smallest);
}
}

Output - 

Smallest Element is - 3 

Using Java 8

IntStream.of(arr).boxed().min(Comparator.naturalOrder()).get().intValue();

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Find More  :-

• Java 8 use Option - avoid NullPointerException
• Producer & Consumer problem solution using BlockingQueue.
• Write your first groovy program.
• Top 10 groovy interview question.
• Difference between groovy and java.
• What is full stack development experience.
• 5 fundamental questions of groovy.
• Write your first java program.
• Reverse string using recursive method in java.
• Comparator Interface with Examples

Find the Missing Number in a list

In this article, we will see how to find the missing number from a list using java.  This is one of important common interview question asked in interview. You can see, how to find all missing numbers from a list. In this program we will use core java or the traditional way using for loop for finding the miss number from a list. Earlier post we had seen how to use stream for finding the missing number. Now we will see how to find one missing number using traditional core java style. 


The logic is very simple here, see the below.

• At first we need to find the MAX number from the list. We need this MAX number because , we need to calculate the SUM of all natural number up to that max number. 
• Then , we need to calculate the sum of all those natural number.
• Then we will subtract each element from the given list from sumOfNaturalNumbers.
• Now, the at the last  the value inside sumOfNaturalNumbers is the missing number.

FindOneMissingNumber.java

package com.javadevelopersguide.lab.basic;
import java.util.ArrayList;
import java.util.Arrays;
/**
 * This program finds the missing number from a list. This is only for one
 * missing number using core java before jdk 8.
 *
 * @author manoj.bardhan
 *
 */
public class FindOneMissingNumber {
public static void main(String[] args) {
ArrayList<Integer> numberList = new ArrayList<Integer>(
Arrays.asList(10, 3, 2, 4, 5, 6, 7, 9, 8, 14, 1, 11, 13));
int sumOfNaturalNumbers = getSumUptoMax(findMax(numberList));
for (int i = 0; i < numberList.size(); i++) {
/*
* Substract each elements from list from sumOfNaturalNumbers and
* the final value will be the missing.
*/
sumOfNaturalNumbers = sumOfNaturalNumbers - numberList.get(i);
}
int missingNumber = sumOfNaturalNumbers;
System.out.println("Missing Number is :: " + missingNumber);
}
// Find the sum of all natural numbers up to limitNumber.
private static int getSumUptoMax(int limitNumber) {
int sum = 0;
for (int i = 1; i <= limitNumber; i++) {
sum = sum + i;
}
return sum;
}
// Find the greatest value from the list
private static int findMax(ArrayList<Integer> numberList) {
int largest = 0;
for (int i = 0; i < numberList.size() - 1; i++) {
if (numberList.get(i) >= largest) {
largest = numberList.get(i);
}
}
return largest;
}
}

Output -

Missing Number is :: 12

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Find More  :-

• Java 8 use Option - avoid NullPointerException
• Producer & Consumer problem solution using BlockingQueue.
• Write your first groovy program.
• Top 10 groovy interview question.
• Difference between groovy and java.
• What is full stack development experience.
• 5 fundamental questions of groovy.
• Write your first java program.
• Reverse string using recursive method in java.
• Comparator Interface with Examples
• Find the smallest number in an array.

Find one missing number from a list of numbers

In this article, we will find the missing number from a list of numbers using java 8.  This is one of important questions asked in interview. This program is to find the only one missing number. Check how to find all missing numbers from a list. In this program we will use only java 8 stream to find the missing number. Earlier post we had seen how to use stream to sort the employee. Check more how find one missing number using traditional core java style. 

FindMissingNumber.java

package com.javadevelopersguide.lab.basic;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Comparator;
import java.util.stream.IntStream;
/**
 * This program finds the missing number from a list. This is only for one
 * missing number. Used the java 8 for this program.
 *
 * @author manoj.bardhan
 *
 */
public class FindMissingNumber {
public static void main(String[] args) {
ArrayList<Integer> numberList = new ArrayList<Integer>(Arrays.asList(1, 3, 2, 4, 5, 6, 7, 9, 10));
// Get the Max value from the List.
int maxValue = numberList.stream().max(Comparator.naturalOrder()).get().intValue();
// Get sum of all natural numbers - upto the above maxvalue
int sumOfAllNumber = IntStream.range(1, maxValue + 1).sum();
// Get the sum of all number inside List.
int sumofList = numberList.stream().mapToInt(Integer::intValue).sum();
// Now print the missing number.
System.out.println("The Missing Number is:: " + (sumOfAllNumber - sumofList));
}
}

Output - 

The Missing Number is:: 8

Happy Learning.

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Find More  :-

• Java 8 use Option - avoid NullPointerException
• Producer & Consumer problem solution using BlockingQueue.
• Write your first groovy program.
• Top 10 groovy interview question.
• Difference between groovy and java.
• What is full stack development experience.
• 5 fundamental questions of groovy.
• Write your first java program.
• Reverse string using recursive method in java.
• Comparator Interface with Examples
• Find the smallest number in an array.

Tavant Technologies Java Interview Questions - Experienced

Tavant Technologies
Round 1:F2F
1) Tell abt ur technical skills
2) How to work with ajax applications?
4) Asked about page factory design concepts.
5) What are the collections u used in ur project?
6) Framework explanation
7) How to find no of rows or columns in a table?
8) Diff b/w interface and abstract class?
9) Various oops concepts used in the project?
10) Roles and responsibilities.
11) SQL queriesa) how to find duplicate records in a table b) Display the name of the emp who is getting         10th maximum salary
12) Logical questions:
i) A 2l bottle and a 4l bottle, By this u have to give me 3l of water? Is it possible? If yes tell me how
ii) 8 balls, having same color and weight, out of that 1 is defective, a physical balance is given, using this how to find the defective one.

Round 2
1. What is run-time polymorphism? Explain with program? Where is it achieved?
2. SQL queriesemp table fieldsename,eid,age
a) Find the name of the emp who has 3rd max age
b) Having clause and where clause
3. Logical questions
a) Cake in round shape, u have to cut the cake by 3 times only, and u have to divide into 8 equal pieces
b) Using 5 zeros, how to make it as 120
c) He gave me a paper, asked me to tore the paper once, to make 3 equal pieces


Round 3- HR+ Managerial round

1. Tell abt ur self
2. Why u r looking for the job?
3. What are the difficulties u faced in ur previous job?
4. He is asking the same questions in different ways for 15 min
5. Framework
6. Difference b/w abstract class and interface.
7. Scenario-an abstract class implements an interface, can the abstract class implement the methods of interface?
8. From that he asked that do u perform auto it scripts in parallel execution?
9. Difference B/w primary key and unique key
10. Can unique key column hold null values? If yes how many null values?
11. Use of super keyword, order of execution
12. Collections u used in the project
13. When array will be used ? and when array list will be used?

All the Best for Interview !!!   



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