30+ BYJU'S Interview Questions and Answers

Memory allocation is the process of assigning memory to programs during runtime.

• Memory allocation is done dynamically during runtime

• It involves allocating and deallocating memory as needed

• Common methods include malloc(), calloc(), and realloc()

• Memory leaks can occur if memory is not properly deallocated

• Memory allocation is important for efficient program execution

onPause() and onStop() methods are called when switching from activity A to B.

• onPause() method is called when the activity is partially visible but still interactive.

• onStop() method is called when the activity is no longer visible to the user.

I have used three jetpack components in my previous projects.

• Used jetpack component A for implementing navigation in Android app

• Utilized jetpack component B for handling lifecycle events in ViewModel

• Integrated jetpack component C for data persistence using Room database

There are four main types of services available in Android: Foreground Service, Background Service, Bound Service, and Intent Service.

• Foreground Service: Runs in the foreground with a visible notification. Example: Music player.

• Background Service: Runs in the background without a user interface. Example: Location tracking service.

• Bound Service: Allows other components to bind to it and interact with it. Example: Music player service bound to a music player activity.

• Intent Ser...read more

A work manager is a tool used in software development to manage and schedule background tasks efficiently.

• Manages background tasks in a way that optimizes resources and improves performance

• Provides features like task prioritization, task chaining, and task cancellation

• Ensures tasks are executed in a timely manner and handles task failures gracefully

• Examples include Android WorkManager for managing background tasks in Android apps

View model will get destroyed when the associated activity or fragment is destroyed.

• View model will get destroyed when the activity or fragment is finished or destroyed.

• If the activity is recreated due to configuration changes like screen rotation, the view model will be recreated as well.

• View model can also be explicitly cleared by calling ViewModel.clear() method.

Garbage collector is a program that automatically frees up memory occupied by objects that are no longer in use.

• Garbage collector is used to prevent memory leaks and improve memory management.

• It automatically identifies and frees up memory occupied by objects that are no longer in use.

• Garbage collector is used in programming languages like Java, C#, and Python.

• It helps to reduce the burden of manual memory management on developers.

• Garbage collector can impact the performance ...read more

I have used GitFlow and feature branch strategies in previous projects.

• Utilized GitFlow branching model for managing feature development and releases

• Created feature branches for each new feature or bug fix

• Merged feature branches back into development branch after code review and testing

• Used tags to mark releases in the master branch

OOPS stands for Object-Oriented Programming System. It includes concepts like polymorphism, abstraction, inheritance, and encapsulation.

• Polymorphism allows objects of different classes to be treated as objects of a common superclass. Example: a shape class with subclasses like circle and square.

• Abstraction is the concept of hiding the implementation details and showing only the necessary features of an object. Example: a car class with methods like start() and stop() without ...read more

Yes, I can implement those in code.

• I have experience in coding and implementing various algorithms and data structures.

• I am proficient in programming languages such as Java, Python, and C++.

• I can provide examples of my previous coding projects upon request.

Clean architecture is a software design approach that separates concerns and enforces a clear separation of layers.

• Clean architecture focuses on separating business logic from implementation details.

• It promotes testability, maintainability, and scalability of the software.

• Common components in clean architecture include entities, use cases, and interfaces.

• Examples of clean architecture patterns include Hexagonal Architecture and Onion Architecture.

Flutter project file structure includes folders like lib, android, ios, and assets.

• The 'lib' folder contains all the Dart code for the project.

• The 'android' folder contains the Android-specific project files.

• The 'ios' folder contains the iOS-specific project files.

• The 'assets' folder is used to store images, fonts, and other static files used in the app.

OOPs stands for Object-Oriented Programming. It is a programming paradigm based on the concept of objects.

• OOPs is based on the four main principles: Encapsulation, Inheritance, Polymorphism, and Abstraction.

• Encapsulation is the process of hiding the implementation details from the user.

• Inheritance is the process of creating new classes from existing classes.

• Polymorphism is the ability of an object to take on many forms.

• Abstraction is the process of hiding the unnecessary deta...read more

Program to print Fibonacci series of N natural numbers.

• Use a loop to generate Fibonacci series up to N numbers.

• Start with 0 and 1 as the first two numbers in the series.

• Each subsequent number is the sum of the two preceding numbers.

• Repeat the process until N numbers are generated.

Deploying a Flutter app on Play Store and App Store involves several steps including creating app bundles, setting up app listings, and submitting for review.

• Create app bundles for Android and IPA files for iOS

• Set up app listings with descriptions, screenshots, and keywords

• Generate signing keys for both platforms

• Submit the app for review on Play Store and App Store

• Wait for approval and release the app to users

Android architecture components are a collection of libraries that help you design robust, testable, and maintainable apps.

• Android architecture components include LiveData, ViewModel, Room, and WorkManager.

• LiveData is an observable data holder class that is lifecycle-aware.

• ViewModel provides data to the UI and survives configuration changes.

• Room is a SQLite object mapping library that provides an abstraction layer over SQLite.

• WorkManager is used for managing deferrable, async...read more

Troubleshooting is the process of identifying, diagnosing, and resolving technical issues or problems.

• Identifying the issue or problem

• Gathering information and data related to the issue

• Analyzing the information to determine the root cause

• Developing and implementing a solution

• Testing the solution to ensure it resolves the issue

• Documenting the troubleshooting process and solution

Sort an array of 0s and 1s with 0s first and 1s last.

• Iterate through the array and count the number of 0s and 1s.

• Create a new array with the counted number of 0s followed by 1s.

• Return the sorted array.

The number of ways n alphabets can be arranged together can be calculated using factorial of n.

• Calculate the factorial of n to find the number of ways the alphabets can be arranged.

• For example, if n=3 (abc), there are 3! = 6 ways to arrange the alphabets (abc, acb, bac, bca, cab, cba).

The main purposes of OOP are encapsulation, inheritance, and polymorphism.

• Encapsulation helps to hide the complexity of the code and protect data from outside access.

• Inheritance allows for the creation of new classes based on existing ones, reducing code duplication.

• Polymorphism enables objects to take on multiple forms and behave differently depending on the context.

• OOP promotes code reusability, modularity, and maintainability.

• Examples of OOP languages include Java, C++, an...read more

Lifecycle component refers to the various stages a software component goes through from creation to deletion.

• Lifecycle component includes creation, initialization, execution, and destruction stages.

• It involves managing resources, handling events, and maintaining state throughout the component's lifespan.

• Examples include Android Activity lifecycle, React component lifecycle, and Angular component lifecycle.

Program to check if a number is prime

• Iterate from 2 to square root of the number and check for divisibility

• If the number is divisible by any number other than 1 and itself, it is not prime

• Return true if the number is prime, false otherwise

I would rate myself an 8 in SQL. I have strong knowledge and experience in writing complex queries and optimizing database performance.

• I have extensive experience writing complex SQL queries

• I am proficient in optimizing database performance

• I have worked on various database management systems such as MySQL, SQL Server, and Oracle

Pillars of OOPs are Abstraction, Encapsulation, Inheritance, and Polymorphism.

• Abstraction: Hiding implementation details and showing only necessary information.

• Encapsulation: Binding data and functions together to protect data from outside interference.

• Inheritance: Creating new classes from existing ones, inheriting properties and methods.

• Polymorphism: Ability of objects to take on multiple forms or behaviors.

MySQL is a specific relational database management system, while SQL is a language used to interact with databases.

• MySQL is a specific RDBMS, while SQL is a language used to interact with databases

• SQL is a standard language for querying and managing databases, while MySQL is a specific implementation of that language

• MySQL is open-source and widely used, while SQL is a language used by many different database systems

Packages are collections of Dart code that provide functionality, while plugins are platform-specific code that interacts with native code.

• Packages are written in Dart and can be used across different platforms.

• Plugins are platform-specific and interact with native code for functionalities like accessing device hardware.

• Examples of packages include http, shared_preferences, while examples of plugins include camera, location.

• Packages are usually published on pub.dev, while plu...read more

Parameters can be used in various ways in software development, such as passing values to functions, setting configuration options, and filtering data.

• Passing values to functions

• Setting configuration options

• Filtering data in queries

SQL query to find nth salary

• Use ORDER BY and LIMIT clauses

• Exclude duplicates using DISTINCT

• Use subquery to find nth salary

Hash map is a data structure that stores key-value pairs and uses hashing to quickly retrieve values.

• Hash map uses a hash function to map keys to indices in an array.

• Collisions can occur when multiple keys map to the same index, which can be resolved using techniques like chaining or open addressing.

• Hash map operations like insertion, deletion, and lookup have an average time complexity of O(1).

Identify the error in the given codes.

• Check for syntax errors

• Look for logical errors

• Ensure proper variable declaration and usage

• Verify if all necessary libraries are imported

• Debug the code step by step

Tableau filters allow users to control the data displayed in visualizations.

• Tableau filters can be applied to dimensions or measures to limit the data shown.

• Common types of Tableau filters include quick filters, context filters, and data source filters.

• Examples of Tableau filters include date filters, range filters, and wildcard filters.