Northcorp Software Java Developer Interview Questions, Process, and Tips

Abstract class can have both abstract and non-abstract methods, while interface can only have abstract methods.

• Abstract class can have constructors, member variables, and methods, while interface cannot.

• A class can implement multiple interfaces but can only extend one abstract class.

• Abstract classes are used to define a common behavior among subclasses, while interfaces are used to define a contract for classes to impl...read more

Abstract classes can have both implemented and abstract methods, while interfaces can only have abstract methods. Abstract classes support single inheritance, interfaces support multiple inheritance.

• Abstract classes can have both implemented and abstract methods, providing more flexibility in design.

• Interfaces can only have abstract methods, promoting a more strict contract for implementing classes.

• Abstract classes sup...read more

Method overloading is when multiple methods in a class have the same name but different parameters.

• Allows multiple methods with the same name but different parameters in a class

• Parameters can differ in number, type, or order

• Compile-time polymorphism

• Example: void print(int a) and void print(String s)

Method overloading allows defining multiple methods with the same name but different parameters.

• Methods must have different parameter types or number of parameters.

• Return type does not matter for method overloading.

• Example: void print(int num) and void print(String text) are valid overloads.

D/W Hashmap and ConcurrentHashmap are both implementations of the Map interface in Java, with the latter being thread-safe.

• D/W Hashmap stands for 'Doubly-Linked Hashmap' and is a custom implementation of a hashmap in Java that maintains insertion order.

• ConcurrentHashmap is a thread-safe implementation of the Map interface in Java, allowing multiple threads to access and modify it concurrently without causing data corru

HashMap is not synchronized and not thread-safe, while ConcurrentHashMap is thread-safe and allows concurrent access.

• HashMap is not synchronized, so it is not safe to use in a multi-threaded environment without external synchronization.

• ConcurrentHashMap uses internal synchronization mechanisms to ensure thread safety, allowing multiple threads to access and modify it concurrently.

• ConcurrentHashMap is designed to handle...read more

A Java developer is responsible for designing, developing, and maintaining Java-based applications.

• Designing and implementing Java applications

• Writing efficient and maintainable code

• Testing and debugging code

• Collaborating with team members to solve technical problems

• Keeping up-to-date with Java technologies and best practices

Develop, test, and maintain Java applications to ensure functionality and performance.

• Write clean and efficient code following best practices

• Test the application thoroughly to identify and fix bugs

• Regularly update and maintain the application to meet changing requirements