10+ Associate Java Developer Interview Questions and Answers for Freshers

No-SQL is a type of database that does not use the traditional tabular structure of relational databases.

• No-SQL databases are used when dealing with large amounts of unstructured or semi-structured data.

• They are suitable for real-time applications, big data, and cloud-based systems.

• Examples of No-SQL databases include MongoDB, Cassandra, and Redis.

OOPS concepts are fundamental principles in object-oriented programming.

• Encapsulation: Bundling data and methods that operate on the data into a single unit. Example: Class Car with properties like make, model, and methods like start(), stop().

• Inheritance: Allows a class to inherit properties and behavior from another class. Example: Class Truck inheriting from class Vehicle.

• Polymorphism: Ability to present the same interface for different data types. Example: Method overload...read more

Polymorphism in Java refers to the ability of a single method to perform different actions based on the object it is acting upon.

• Types of polymorphism: compile-time polymorphism (method overloading) and runtime polymorphism (method overriding)

• Method overloading: multiple methods in the same class with the same name but different parameters

• Example of method overloading: public void display(int a) and public void display(int a, int b)

• Method overriding: a subclass provides a spe...read more

DBMS stands for Database Management System. R-DBMS is a relational database management system which stores data in tables with relationships.

• DBMS is a software system that allows users to define, create, maintain and control access to the database.

• R-DBMS is a type of DBMS that stores data in tables with relationships between the tables.

• R-DBMS uses Structured Query Language (SQL) for accessing and managing the data.

• Examples of R-DBMS include MySQL, Oracle, SQL Server, and Post...read more

I am familiar with Java 8 and Java 11.

• Familiar with features like lambda expressions, streams, and default methods in Java 8.

• Experience with features like local-variable type inference, HTTP/2 client, and new string methods in Java 11.

Disadvantages of DBMS include high cost, complexity, potential for data loss, and security vulnerabilities.

• High cost of implementation and maintenance

• Complexity in managing and scaling the database

• Potential for data loss due to system failures or human errors

• Security vulnerabilities that can lead to data breaches

• Dependency on a single vendor for support and updates

HashMap is a data structure in Java that stores key-value pairs and allows fast retrieval of values based on keys.

• HashMap implements the Map interface and uses hashing to store elements.

• It allows one null key and multiple null values.

• Example: HashMap map = new HashMap<>(); map.put("apple", 5); int value = map.get("apple");

Java is a versatile programming language known for its platform independence, object-oriented features, and robust standard library.

• Platform independence - Java programs can run on any platform that has a Java Virtual Machine (JVM)

• Object-oriented - Java supports the principles of encapsulation, inheritance, and polymorphism

• Robust standard library - Java provides a rich set of APIs for tasks like networking, I/O, and database access

Both Java and Python have their own strengths and weaknesses, and the choice depends on the specific requirements of the project.

• Java is a statically typed language, while Python is dynamically typed.

• Java is known for its performance and scalability, making it suitable for large-scale enterprise applications.

• Python is known for its simplicity and readability, making it a popular choice for beginners and rapid development.

• Java has a strong ecosystem and extensive libraries for...read more