What will be the output of the following code?
int x = 5;
int y = ++x + x++;
System.out.println(y);
Answer: B
++x makes x=6 (pre-increment). Then x++ uses 6 and increments to 7. So y = 6 + 6 = 12.
Q.562Medium
Which of the following sorting algorithms is most efficient for nearly sorted data?
Answer: C
Insertion Sort has O(n) time complexity for nearly sorted data, making it the most efficient choice.
Q.563Medium
What will be printed?
String s1 = new String('Amazon');
String s2 = new String('Amazon');
System.out.println(s1 == s2);
Answer: B
== compares memory references. Both s1 and s2 are different objects, so it prints false. Use .equals() for value comparison.
Q.564Medium
What is the primary purpose of a hash function?
Answer: B
A hash function takes input data and produces a fixed-size output (hash value), useful for hash tables and data indexing.
Q.565Hard
Which of the following is a characteristic of a good hash function?
Answer: D
Good hash functions are deterministic (same input gives same output), uniformly distribute values, and minimize collisions.
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Q.566Easy
In the context of REST APIs, what does POST primarily do?
Answer: B
POST method is used to create new resources on the server. GET retrieves, PUT/PATCH updates, DELETE removes.
Q.567Medium
What is the main advantage of using microservices architecture?
Answer: B
Microservices allow independent scaling, deployment, and technology choices. However, they can increase operational complexity.
Q.568Easy
Which design pattern is used when you want to ensure a class has only one instance?
Answer: B
Singleton Pattern restricts a class to have only one instance and provides a global access point to it.
Q.569Medium
What will be the output?
List<Integer> list = new ArrayList<>();
list.add(1);
list.add(2);
list.add(3);
list.remove(1);
System.out.println(list);
Answer: A
list.remove(1) removes the element at index 1 (which is 2), leaving [1, 3].
Q.570Medium
What is the difference between ArrayList and LinkedList in Java?
Answer: C
ArrayList has O(1) random access but O(n) insertion/deletion. LinkedList has O(n) access but O(1) insertion/deletion.
Q.571Easy
Which of the following is NOT a principle of object-oriented programming?
Answer: D
The four OOP principles are Inheritance, Encapsulation, Polymorphism, and Abstraction. 'Materialization' is not an OOP principle.
Q.572Easy
What is the purpose of the 'try-catch' block in Java?
Answer: B
try-catch blocks allow you to handle exceptions without crashing the program, providing graceful error handling.
Q.573Hard
If a HashMap has 1000 entries and the load factor is 0.75, at what capacity will it resize?
Answer: C
Resize occurs when entries exceed capacity × load factor. If 1000 entries at 0.75 load factor, capacity = 01000.75 = 1333
Q.574Medium
What is the time complexity of accessing an element in a balanced Binary Search Tree?
Answer: B
In a balanced BST, the height is log n, so searching takes O(log n) time.
Q.575Easy
Which protocol is used for secure data transmission over the internet?
Answer: B
HTTPS (HTTP Secure) encrypts data in transit using SSL/TLS. Other protocols lack this encryption.
Q.576Easy
What does the SELECT * query do in SQL?
Answer: B
SELECT * retrieves all columns and rows from a table. * is a wildcard meaning 'all columns'.
Q.577Medium
A train travels from City A to City B at 60 km/h and returns from B to A at 40 km/h. If the total journey time is 10 hours, what is the distance between City A and City B?
Answer: A
Let distance = d km. Time A to B = d/60 hours, Time B to A = d/40 hours. Total time: d/60 + d/40 = 10. LCM(60,40)=120, so (2d + 3d)/120 = 10, giving 5d/120 = 10, thus d = 240 km.
Q.578Easy
In a sequence, each term is obtained by adding the previous two terms. If the 1st term is 2 and 2nd term is 3, what is the 6th term?
Answer: B
Fibonacci-like sequence: T1=2, T2=3, T3=5, T4=8, T5=13, T6=21. Each term = sum of previous two terms.
Q.579Easy
If PAPER is coded as 16-1-16-5-18, then PENCIL would be coded as?
Answer: A
Each letter is coded as its position in the alphabet: P=16, A=1, P=16, E=5, R=18. Similarly, PENCIL: P=16, E=5, N=14, C=3, I=9, L=12.
Q.580Easy
Four friends A, B, C, and D have different salaries. C earns more than A but less than D. B earns more than D. Who has the highest salary?
Answer: B
From given conditions: A < C < D and D < B. This means B > D > C > A. Therefore, B has the highest salary.
