VV TECH PRIVATE LIMITED Senior Java Fullstack Developer Interview Questions, Process, and Tips

Function Overriding is a concept in object-oriented programming where a subclass provides a specific implementation of a method that is already provided by its parent class.

• In Function Overriding, a subclass can provide a specific implementation of a method that is already defined in its parent class.

• The method in the subclass must have the same name, return type, and parameters as the method in the parent class to ove...read more

Using LINQ query to order data in C#

• Use the OrderBy method to sort data in ascending order

• Use the OrderByDescending method to sort data in descending order

• You can also use ThenBy and ThenByDescending for secondary sorting

Out parameter is used to pass data out of a method or function.

• Out parameters are used when a method needs to return multiple values.

• They are declared using the 'out' keyword in C#.

• Example: void CalculateArea(int length, int width, out int area) { area = length * width; }

Reflection in C# allows for inspecting and manipulating metadata of types at runtime.

• Reflection is used to dynamically create instances of types, access properties, and invoke methods.

• Examples include using reflection to load assemblies at runtime, inspect attributes of types, and generate code dynamically.

• Reflection can be slow and should be used judiciously due to performance overhead.

Find the second largest element from array of strings

• Sort the array in descending order

• Access the element at index 1 to get the second largest element

Failsafe integrators prioritize system stability by handling errors gracefully, while fail fast integrators prioritize quick detection and resolution of errors.

• Failsafe integrators focus on ensuring the system continues to function even in the presence of errors.

• Fail fast integrators aim to quickly identify and address errors to prevent further issues.

• Failsafe integrators often use techniques like retries, circuit brea...read more

JVM is the virtual machine that runs Java bytecode, JRE is the runtime environment for Java programs, and JDK is the development kit for creating Java applications.

• JVM (Java Virtual Machine) is responsible for running Java bytecode on different platforms.

• JRE (Java Runtime Environment) includes JVM, libraries, and other components necessary to run Java applications.

• JDK (Java Development Kit) is a software development ki...read more

String is immutable in Java to ensure security, thread safety, and optimization.

• Immutable strings prevent accidental changes to sensitive data like passwords.

• Immutable strings allow for safe sharing of string literals across multiple threads.

• Immutable strings enable string pooling for memory optimization.

• Example: String str = "Hello"; str.concat(" World"); // str remains "Hello"

Overloading is having multiple methods with the same name but different parameters, while overriding is implementing a method in a subclass with the same signature as in the superclass.

• Overloading allows different methods to have the same name but different parameters.

• Overriding involves implementing a method in a subclass with the same signature as in the superclass.

• Overloading is determined at compile time based on t...read more

SAGA pattern is a design pattern used in microservices architecture to manage distributed transactions.

• SAGA pattern breaks down a long-running transaction into a series of smaller, independent transactions.

• Each step in the SAGA pattern is a separate service that communicates with other services through events.

• If a step fails, compensating transactions are executed to rollback the changes made by previous steps.

• Example:...read more

API stands for Application Programming Interface. It defines the methods and data formats that applications can use to communicate with each other.

• API is a set of rules and protocols that allows different software applications to communicate with each other.

• To secure an API, you can use authentication methods like OAuth, API keys, or JWT tokens.

• Implementing encryption (HTTPS) and rate limiting can also enhance API secu...read more

Find duplicate characters in a given array of strings

• Iterate through each string in the array

• For each string, iterate through each character and store the count in a hashmap

• If the count of any character is greater than 1, it is a duplicate

Code for REST API using Spring Boot with annotations

• Use @RestController annotation to define the class as a REST controller

• Use @RequestMapping annotation to map HTTP requests to handler methods

• Use @GetMapping, @PostMapping, @PutMapping, @DeleteMapping annotations for specific HTTP methods

• Use @PathVariable annotation to extract values from the URI

• Use @RequestBody annotation to bind HTTP request body to a method paramete

A simple program to print 'fizz' for multiples of 3, 'buzz' for multiples of 5, and 'fizzbuzz' for multiples of both.

• Iterate through numbers from 1 to n.

• Use modulo operator to check divisibility by 3 and 5.

• Print 'fizz', 'buzz', or 'fizzbuzz' accordingly.

Yes, classes implementing an interface must implement interface methods.

• Classes implementing an interface must provide concrete implementations for all methods declared in the interface.

• Failure to implement all interface methods will result in a compilation error.

• Interfaces are used to define a contract that implementing classes must adhere to.