10+ Interview Questions and Answers

Method for deleting a node from a Linked List

• Find the node to be deleted

• Update the previous node's next pointer to skip the deleted node

• Free the memory occupied by the deleted node

Code to check if two strings are anagrams of each other.

• Create two character arrays from the strings

• Sort the arrays

• Compare the sorted arrays

Creating a custom immutable class in Java

• Make the class final

• Make all fields private and final

• Do not provide any setter methods

• Provide a constructor to initialize all fields

• Override equals() and hashCode() methods

• Prevent modification of mutable objects passed in constructor

String is immutable because it ensures data integrity and allows for efficient memory management.

• Immutable strings prevent accidental modification of data.

• Immutable strings can be easily shared and reused, improving memory efficiency.

• Immutable strings enable efficient string interning and caching.

• Immutable strings support thread safety in concurrent environments.

Time complexity of linked list operations is O(n) for traversal, insertion and deletion.

• Traversal, insertion and deletion in linked lists take linear time.

• Insertion and deletion at the beginning of the list is faster than at the end.

• Doubly linked lists have slightly higher time complexity due to maintaining two pointers.

Yes, @RequestParam has a default value if not specified.

• If a @RequestParam is not provided in the request, it will use its default value.

• The default value can be set using the 'defaultValue' attribute of @RequestParam annotation.

• If no default value is specified, the parameter will be considered as required and an exception will be thrown if not provided.

Abstract classes are required to provide a common interface and share code among related classes.

• Abstract classes allow for code reusability and promote modular design.

• They provide a common interface for a group of related classes.

• Abstract classes can define abstract methods that must be implemented by subclasses.

• They can also provide default implementations for common methods.

• Abstract classes cannot be instantiated, but can be used as a reference type.

using namespace std; is a directive in C++ that allows the programmer to use all elements of the standard C++ library without specifying the std:: prefix.

• It is used to avoid having to write std:: before standard library elements.

• It should be used with caution as it can lead to naming conflicts.

• Example: cout << 'Hello, World!'; instead of std::cout << 'Hello, World!';

To reverse a string, iterate through the string and append each character to a new string in reverse order.

• Create an empty string to store the reversed string

• Iterate through the original string from the end to the beginning

• Append each character to the new string

• Return the new string

Polymorphism is the ability of a function or method to behave differently based on the object it is acting upon.

• Polymorphism allows objects of different classes to be treated as objects of a common superclass.

• There are two types of polymorphism: compile-time (method overloading) and runtime (method overriding).

• Example: Animal class with methods like eat() can be inherited by classes like Dog and Cat, which can override the eat() method.

OOD (Object-Oriented Design) is essential for creating modular, reusable, and maintainable software systems.

• OOD helps in organizing code into manageable components

• Encourages code reusability through inheritance and polymorphism

• Facilitates easier maintenance and updates

• Promotes scalability and flexibility in software development

• Enables better collaboration among team members