Core Java - Interview Questions and Answers for 'Array' | 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.

Submit Question

Interview Questions and Answers - Order By Newest

Q41. Which of the two - Arrays or LinkedList - is a better data structure for implementing Queue ? and Why ?

^{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 Arraylist linkedlist queue collections}

Q42. Write an efficient program for printing k largest elements in an array. Elements in array can be in any order.

^{This question was recently asked at 'Amazon'.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 arrays coding code Asked in 1 Companies}

Q43. Which of the following - arrays or LinkedList allow elements to be accessed using index and how ?

Ans. Arrays allows elements to be accessed directly using the index.

As Array elements are stored in continuous memory locations it's very easy to find the memory address of any element using the formula as following

Memory Address of Array start or index 0 + ( Size of array element * Index )

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

_{Like Discuss Correct / Improve arrays linkedlist}

Q44. Find Intersection/union between two arrays.

^{This question was recently asked at 'Bristlecone,Amazon Lab126,Amazon,Microsoft,Facebook,NCR,Google'.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 arrays code coding Asked in 7 Companies frequent}

Q45. Write code to sort an array.

Ans. https://www.geeksforgeeks.org/arrays-sort-in-java-with-examples/

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

_{Like Discuss Correct / Improve array sorting Asked in 16 Companies basic frequent}

Q46. How arrays work internally ?

^{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 arrays}

Q47. Can we change the size of array once created ?

Ans. No. Arrays cannot resize dynamically.

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

_{Like Discuss Correct / Improve array array size Basic}

Q48. What is ArrayStoreException ?

Ans. It's an exception that is thrown when we attempt to add value of an incompatible type to an array.

For example -

Object[] strArray = new String[2];
strArray[0] = 5;

In this code, strArray reference of type Object has currently been assigned the String array but at line 2 we are trying to add an integer value.

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

_{Like Discuss Correct / Improve arrays ArrayStoreException}

Q49. What is an anonymous array in 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 anonymous arrays}

Q50. What are jagged arrays ?

Ans. an array of different sizes

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

_{Like Discuss Correct / Improve arrays jagged arrays}

Q51. Are Arrays treated like primitives or like objects in 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 arrays}

Q52. How can we check equality for Arrays in Java ?

Ans. You call the method java.util.Arrays.equals(Object[] a, Object[] a2)?

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

_{Like Discuss Correct / Improve arrays}

Q53. Are arrays Thread Safe ?

Ans. Yes

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

_{Like Discuss Correct / Improve arrays concurrency Asked in 1 Companies}

Q54. What is the time and space complexity for different operations for arrays ?

^{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 arrays}

Q55. Difference between Arrays and LinkedList ?

^{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 arrays vs linkedlist}

Q56. Can we have 3 dimensional arrays in Java ?

Ans. Yes

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

_{Like Discuss Correct / Improve arrays}

Q57. Can we make array volatile in Java ?

Ans. Yes, you can make an array (both primitive and reference type array e.g. an int array and String array) volatile in Java but only changes to reference pointing to an array will be visible to all threads, not the whole array

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

_{Like Discuss Correct / Improve arrays volatile}

Q58. Is this array declaration correct ? If not , Why ?

String[] strArray = new String[];

Ans. No, We haven't specified the size of array to be initialized.

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

_{Like Discuss Correct / Improve arrays array initialization}

Q59. Is this array initialization correct ? If Yes, What will be the size of array ?

String[] strArray = new String[]{"Buggy","Bread"};

Ans. Yes, size of the array will be 2.

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

_{Like Discuss Correct / Improve arrays array initialization}

Q60. Is this array initialization correct ? If Yes, What will be the size of array ?

String[] strArray = new String[3]{"Buggy","Bread"};

Ans. No. It will result in error saying "Cannot define dimension expressions when an array initializer is provided"

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

_{Like Discuss Correct / Improve arrays array initialization}

Q61. Is this code valid

String[] strArray = new String[2];
strArray.length = 5;

Ans. It will give compile time error saying "The final field array.length cannot be assigned"

Arrays once initialized cannot be resized.

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

_{Like Discuss Correct / Improve arrays array initialization}

Q62. What is the problem with this code

String[] strArray = new String[2];
strArray[0] = 5;

Ans. We are trying to add an integer element to an array of String. Will give compile time error.

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

_{Like Discuss Correct / Improve arrays}

Q63. Will this give compile time error ?

Object[] strArray = new String[2];
strArray[0] = 5;

Ans. No. But It will throw ArrayStoreException at runtime.

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

_{Like Discuss Correct / Improve ArrayStoreException arrays}

Q64. Write a Program to Find the maximum sum of the sub array ?

^{This question was recently asked at 'Reddit'.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 Maximum subarray variant arrays sub array subarray Asked in 1 Companies}

Q65. Difference between List and ArrayList ?

Ans. List is an interface whereas ArrayList is an implementation of List.

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

_{Like Discuss Correct / Improve list arraylist list vs arraylist difference between collections Asked in 2 Companies basic}

Q66. difference between ArrayList and array ?

Ans. ArrayList is a variable length collection class whereas arrays are fixed length primitive structure.

We can use generics with arraylist but not with arrays.

We can store primitive data types within arrays but can't with ArrayList. In ArrayList that needs to be converted to Wrapper objects.

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

_{Like Discuss Correct / Improve arraylist arrays collection classes collections basic frequent}

Q67. Difference between ArrayList and HashSet ?

Ans. ArrayList is a list , i.e an implementation of List interface whereas HashSet is a Set and an implementation of Set interface.

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

_{Like Discuss Correct / Improve arraylist hashset}

Q68. Write a program to make an array act as a set.

Ans. public Set convertArrayToList(T array[]) {
Set set = new HashSet<>(Arrays.asList(array));
return set;
}

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

_{Like Discuss Correct / Improve arrays collections set Asked in 1 Companies}

Q69. How can we create an arraylist of unique values ?

Ans. We can put the value in a set to enforce uniqueness and then dum those value into an arraylist.

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

_{Like Discuss Correct / Improve arraylist design collections}

Q70. What will be the output of exceuting main method ?

public static void main(String[] args){
      List list = new ArrayList();
      list.add(1);
      list.add(2);
      list.add(3);
      System.out.println(list);
   }

a. 1,2,3

b. Order cannot be determined

c. compilation error

d. 3,2,1

Ans.a. 1,2,3

previous 30