Java Software Developer Interview Questions

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Round 1: 30 MCQ questions related to Core Java . ( If you attend 14-15 correctly you're through) Round 2: F2F , Basic Core Java Questions like: - OOPs concept - BST node finding - Reverse Linked List - Find duplicates Your code should be efficient to mark you above others. Round 3 : This round contains tough Core Java questions and they will test your understanding in Multithreading (Advance) and other untouched Java topics. This round itself contains Design level questions as well: - Design a Booking application ( What all features would you like to see ?) Like multithreading should be there in order to check none of single seat can be occupied by multiple persons - Implement Map
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Java Software Developer

Interviewed at Oracle

3.5
Jul 16, 2018

Round 1: 30 MCQ questions related to Core Java . ( If you attend 14-15 correctly you're through) Round 2: F2F , Basic Core Java Questions like: - OOPs concept - BST node finding - Reverse Linked List - Find duplicates Your code should be efficient to mark you above others. Round 3 : This round contains tough Core Java questions and they will test your understanding in Multithreading (Advance) and other untouched Java topics. This round itself contains Design level questions as well: - Design a Booking application ( What all features would you like to see ?) Like multithreading should be there in order to check none of single seat can be occupied by multiple persons - Implement Map

1st Technical Round: 1. Method overriding rules? 2. Output? • //classes will compile fine bcos both r throwing run time exceptions • class TestOverride { • void solution() throws NullPointerException { • System.out.println("super"); • } • } • • class TestSubOverride extends TestOverride { • void solution() throws RuntimeException { • System.out.println("sub"); • } • } 2. Given array {4,5,6,1,2,4}; how do u search particular element ex:1? Ans: he was looking for best search algorithm – ans is binary search algorithm 3. Consider I have huge data which is stored randomly, which data structure is best for retrieval with performance of O(1)? Ans: Hashmap bcos of performance O(1) always 4. Write a code to delete a node from LinkedList 5. Write a simple code for Threading. 6. What is difference between callable and Runnable? 7. What is functional interface? 8. Why functional interface should have only one abstract method why not more than one? 9. When we use lamda expressions? 10. What is difference between IOC and dependency injection? 11. Why do we need dependency injection? 12. Scopes of bean in spring? 2nd Technical Round: 1. Why Java is so popular? In depth answer 2. Given Name, write code to print all combinations using that. 3. Given array, {1,2,3,4,5,6,7,8} and {4,1,2,5,1,2,3,4,5,6,7,8}, at any given position how do you find out array is sorted or not. (Circular sorting)
Jul 9, 2018

1st Technical Round: 1. Method overriding rules? 2. Output? • //classes will compile fine bcos both r throwing run time exceptions • class TestOverride { • void solution() throws NullPointerException { • System.out.println("super"); • } • } • • class TestSubOverride extends TestOverride { • void solution() throws RuntimeException { • System.out.println("sub"); • } • } 2. Given array {4,5,6,1,2,4}; how do u search particular element ex:1? Ans: he was looking for best search algorithm – ans is binary search algorithm 3. Consider I have huge data which is stored randomly, which data structure is best for retrieval with performance of O(1)? Ans: Hashmap bcos of performance O(1) always 4. Write a code to delete a node from LinkedList 5. Write a simple code for Threading. 6. What is difference between callable and Runnable? 7. What is functional interface? 8. Why functional interface should have only one abstract method why not more than one? 9. When we use lamda expressions? 10. What is difference between IOC and dependency injection? 11. Why do we need dependency injection? 12. Scopes of bean in spring? 2nd Technical Round: 1. Why Java is so popular? In depth answer 2. Given Name, write code to print all combinations using that. 3. Given array, {1,2,3,4,5,6,7,8} and {4,1,2,5,1,2,3,4,5,6,7,8}, at any given position how do you find out array is sorted or not. (Circular sorting)

1. split array int smaller arrays based on given size. int[] original = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9}; int splitSize = 3; /* expected Output [0, 1, 2] [3, 4, 5] [6, 7, 8] [9] */ 2.Flatten object array. Object[] array = { 1, 2, new Object[]{ 3, 4, new Object[]{ 5 }, 6, 7 }, 8, 9, 10 };
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Software Engineer - Java Developer

Interviewed at Wissen Infotech

3.8
Jun 12, 2023

1. split array int smaller arrays based on given size. int[] original = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9}; int splitSize = 3; /* expected Output [0, 1, 2] [3, 4, 5] [6, 7, 8] [9] */ 2.Flatten object array. Object[] array = { 1, 2, new Object[]{ 3, 4, new Object[]{ 5 }, 6, 7 }, 8, 9, 10 };

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