30+ Gerab National Enterprises Interview Questions and Answers

Yes, static methods can be overloaded but not overridden.

• Overloading is having multiple methods with the same name but different parameters.

• Static methods cannot be overridden as they belong to the class and not the instance.

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

Query parameters are appended to the end of a URL after a '?' while path parameters are part of the URL path.

• Query parameters are optional and can be used to filter or sort data.

• Path parameters are mandatory and used to identify a specific resource.

• Query parameters are separated by '&' while path parameters are separated by '/'.

• Example of query parameter: www.example.com/search?q=keyword

• Example of path parameter: www.example.com/users/123

Postman allows logging of request and response through its console feature.

• Postman's console feature allows logging of request and response data

• To enable logging, go to the console tab and select 'All' from the dropdown menu

• The console displays the request and response data along with other details like headers and status codes

JAVA program to reverse a string and repeated occurrence with and without loops

• Use StringBuilder class to reverse the string without loops

• Use for loop to reverse the string with loops

• Use HashMap to count the occurrence of each character

• Use LinkedHashMap to maintain the order of occurrence

Count set bits in a 32-bit integer in linear time

• Use bit manipulation to count set bits

• Divide the integer into 16-bit chunks and count set bits in each chunk

• Use lookup tables to count set bits in each 8-bit chunk

• Use parallel processing to count set bits in multiple integers simultaneously

Method Overloading is having multiple methods with the same name but different parameters. Method Overriding is having a method in a subclass with the same name and parameters as a method in its superclass.

• Method Overloading is done in the same class while Method Overriding is done in different classes.

• Method Overloading is used to add more behavior to a method while Method Overriding is used to change the behavior of a method.

• Method Overloading is resolved at compile-time wh...read more

JAVA program to reverse a String and count repeated occurrences.

• Use StringBuilder to reverse the String.

• Use a HashMap to count the occurrences of each character.

• Iterate through the HashMap to print the repeated characters and their count.

To set the same header name in API, use the 'setHeader' method in the API request.

• Identify the header name that needs to be set.

• Use the 'setHeader' method in the API request to set the header name.

• Pass the header name and value as parameters to the 'setHeader' method.

• Example: request.setHeader('Authorization', 'Bearer ')

Random and dynamic data requests are requests for data that is not predetermined or fixed.

• Random data requests are requests for data that is not predetermined or fixed.

• Dynamic data requests are requests for data that changes frequently.

• Examples of random and dynamic data requests include user input, sensor data, and API responses.

Frequently faced API response codes include 200, 400, 401, 404, and 500.

• 200 - OK: Successful request

• 400 - Bad Request: Invalid input or missing parameters

• 401 - Unauthorized: Authentication failure

• 404 - Not Found: Requested resource not found

• 500 - Internal Server Error: Server-side error

CURL is a command-line tool used to transfer data to or from a server using various protocols.

• CURL stands for 'Client URL'

• It supports various protocols like HTTP, FTP, SMTP, etc.

• It can be used to send requests and receive responses from a server

• It can be used to test APIs and web services

• Example: curl https://www.example.com -v

Find two integers in an array whose sum is closest to zero.

• Sort the array in ascending order.

• Initialize two pointers at the beginning and end of the array.

• Move the pointers towards each other until the sum is closest to zero.

String is immutable because it cannot be changed once created.

• String objects are stored in a constant pool, which cannot be modified.

• Any operation on a string creates a new string object.

• This ensures thread safety and prevents unintended changes to the string.

• For example, if a string is used as a key in a map, its immutability guarantees that the key will not change.

BDD focuses on behavior and collaboration while TDD focuses on testing and development.

• BDD involves collaboration between developers, testers, and business stakeholders to define behavior in a common language

• TDD involves writing tests before writing code to ensure code meets requirements

• BDD uses scenarios to describe behavior while TDD uses test cases to verify functionality

• BDD is more focused on the end-user experience while TDD is more focused on code functionality

• BDD can b...read more

Waits in Selenium are used to synchronize the test script execution with the application's response.

• Waits are used to handle synchronization issues in Selenium

• There are two types of waits: Implicit and Explicit

• Implicit waits wait for a certain amount of time before throwing an exception

• Explicit waits wait for a certain condition to occur before proceeding with the test script

• Examples of explicit waits include: WebDriverWait, FluentWait

API request methods are the actions that can be performed on a web API.

• API request methods include GET, POST, PUT, DELETE, PATCH, and OPTIONS.

• GET is used to retrieve data from the server.

• POST is used to submit data to the server.

• PUT is used to update existing data on the server.

• DELETE is used to delete data from the server.

• PATCH is used to partially update existing data on the server.

• OPTIONS is used to retrieve information about the communication options available for a resou...read more

Code to delete duplicate nodes in a sorted linked list

• Traverse the linked list and compare adjacent nodes

• If nodes are equal, delete one of them

• Repeat until all duplicates are removed

OOPS is a programming paradigm based on the concept of objects that interact with each other to perform tasks.

• OOPS stands for Object-Oriented Programming System

• It focuses on creating reusable code and organizing it into objects

• It includes concepts like inheritance, encapsulation, polymorphism, and abstraction

• Example: A car object can have properties like color, model, and speed, and methods like start, stop, and accelerate

• OOPS languages include Java, C++, Python, and Ruby

Interview questions for QA Engineer including Selenium, Rest API, Java collection, and programming based on data structures.

• Demonstrate ability to write Selenium code from scratch

• Show proficiency in writing Rest API code from scratch

• Exhibit knowledge of Java collection and its implementation

• Be able to write programs based on data structures like counting each element of a string and finding duplicates

• Use algorithms with O(n) complexity instead of O(n^2)

• Have a strong understan...read more

Files are preferred over databases for certain types of data and applications.

• Files are faster for small amounts of data.

• Files are easier to manage and backup.

• Files are more flexible for certain types of data, such as images or videos.

• Databases are better for complex data relationships and queries.

• Databases are more secure and scalable for large amounts of data.

• The choice between files and databases depends on the specific needs of the application.

Printing all root to leaf paths in a binary search tree

• Traverse the tree recursively and keep track of the current path

• When a leaf node is reached, add the current path to the list of paths

• Print all the paths in the list

• Use an array of strings to store the paths

To determine the width of a binary tree using breadth-wise traversal, we need to count the number of nodes at each level.

• Perform a breadth-first traversal of the binary tree

• Count the number of nodes at each level

• Keep track of the maximum number of nodes seen at any level

• Return the maximum number of nodes seen

Kafka is a distributed streaming platform that allows for real-time data processing. Data is not persisted permanently to optimize performance.

• Kafka is designed for real-time data processing and streaming, not for long-term storage.

• Data is stored in Kafka for a configurable amount of time, after which it is automatically deleted.

• Persisting data permanently would require additional storage and slow down performance.

• Kafka's architecture allows for high throughput and low latenc...read more

Print a matrix in spiral form

• Iterate through the matrix in a spiral pattern, printing each element

• Keep track of the boundaries of the matrix as you move along

• Handle cases where the matrix is not a perfect square separately

Use dynamic programming to find the longest increasing decreasing subsequence in an array.

• Use dynamic programming to keep track of the length of the longest increasing subsequence ending at each index.

• Similarly, keep track of the length of the longest decreasing subsequence starting at each index.

• Combine the two to find the longest increasing decreasing subsequence.

MongoDB is a document-oriented database while Cassandra is a column-family database.

• MongoDB is better suited for complex queries and data modeling.

• Cassandra is better for write-heavy workloads and high availability.

• MongoDB has a flexible schema while Cassandra has a fixed schema.

• MongoDB supports ACID transactions while Cassandra supports eventual consistency.

• MongoDB is more popular for web applications while Cassandra is more popular for IoT and real-time analytics.

Program to find all paths in a binary matrix n*n

• Use backtracking algorithm to explore all possible paths

• Start from the top-left corner and explore all possible paths

• Mark visited cells to avoid revisiting them

• Terminate the search when all possible paths have been explored

• Return all the valid paths found

I prioritize the issue based on severity, communicate with relevant teams, and provide regular updates to the customer.

• Prioritize issues based on severity to ensure critical issues are resolved first

• Communicate effectively with relevant teams to address the issue promptly

• Provide regular updates to the customer on the progress of issue resolution

Normalizations are used to standardize data by removing redundancies and inconsistencies.

• Normalizations help in organizing data in a consistent and efficient manner.

• They reduce data redundancy by eliminating duplicate information.

• Normalization ensures data integrity and accuracy by avoiding inconsistencies.

• Examples include normalizing database tables to reduce data duplication and improve query performance.

Segment customers based on their needs, behavior, and demographics.

• Segment based on customer needs and pain points

• Segment based on customer behavior and usage patterns

• Segment based on demographics such as age, location, industry, etc.

AWS SQS (Simple Queue Service) is a fully managed message queuing service that enables decoupling of components in a distributed system.

• Used for storing messages in a queue before they are processed by a consumer

• Supports distributed systems by enabling asynchronous communication between components

• Helps in decoupling different parts of a system, improving scalability and fault tolerance

• Messages can be stored in SQS for up to 14 days before being processed

Project framework is a structure that provides guidelines, tools, and libraries for developing software applications.

• Provides a foundation for organizing code and implementing best practices

• Includes libraries, tools, and templates to streamline development process

• Can be specific to a programming language or technology stack

• Examples: Angular for front-end web development, Spring for Java applications