20+ Interview Questions and Answers

Abstract class is a class that cannot be instantiated and is used as a blueprint for other classes.

• Abstract class can have abstract methods that must be implemented by its subclasses.

• Real life example of abstraction is a vehicle class with abstract methods like start() and stop().

• Subclasses like Car and Bike can implement these abstract methods in their own way.

Check if a number is divisible by 2 using modulo operator.

• Use the modulo operator (%) to check if the remainder is 0 when dividing the number by 2.

• If the remainder is 0, then the number is divisible by 2.

• For example, if num % 2 == 0, then the number is divisible by 2.

To find palindrome words in a sentence, split the sentence into words and check if each word is equal to its reverse.

• Split the sentence into words using whitespace as a delimiter

• Iterate through each word and check if it is equal to its reverse

• If a word is a palindrome, add it to the list of palindrome words

• Consider case-insensitivity while checking for palindromes

Code to print prime numbers in a given range

• Iterate through numbers in the range and check if each number is prime

• Use a nested loop to check divisibility of each number by numbers less than itself

• Print the number if it is prime

Access modifiers are keywords in programming languages that define the accessibility of classes, methods, and variables.

• Access modifiers include public, private, protected, and default (package-private) in Java.

• Public access allows classes, methods, and variables to be accessed from any other class.

• Private access restricts access to only within the same class.

• Protected access allows access within the same package or subclasses.

• Default access allows access only within the same...read more

Classes are blueprints for creating objects in object-oriented programming. Objects are instances of classes.

• Classes define the properties and behaviors of objects.

• Objects are instances of classes that can hold data and perform actions.

• Classes can inherit properties and behaviors from other classes.

• Objects can interact with each other by calling methods or accessing properties.

• Example: Class 'Car' can have properties like 'color' and 'speed', and objects of class 'Car' can be...read more

OOPs is a programming paradigm based on the concept of objects that interact with each other.

• OOPs stands for Object-Oriented Programming.

• It focuses on the creation of objects that have properties and methods.

• Encapsulation, Inheritance, Polymorphism, and Abstraction are the four main pillars of OOPs.

• Design patterns are reusable solutions to common software problems.

• Some popular design patterns are Singleton, Factory, Observer, and Decorator.

BBT stands for Behavior-Based Testing, a software testing technique that focuses on the behavior of the system under test.

• BBT involves creating test cases based on the expected behavior of the system

• It is a black-box testing technique that does not require knowledge of the internal workings of the system

• BBT can be used to test both functional and non-functional requirements

• Examples of BBT tools include Selenium, Cucumber, and FitNesse

A high severity low priority bug is a software defect that has a significant impact on the system but can be deferred for a later release.

• It is a bug that affects a critical functionality of the system

• It does not require an immediate fix and can be postponed

• It may not affect the end user experience directly

• It can be fixed in a future release or patch

• Examples include cosmetic issues, minor UI glitches, etc.

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

• Oops concept focuses on creating objects that contain data in the form of fields (attributes) and code in the form of procedures (methods).

• It allows for the creation of reusable code and modular programs.

• Encapsulation, inheritance, polymorphism, and abstraction are the four main principles of Oops concept.

• Example: Inheritance allows a class to inherit properties a...read more

Object-oriented programming concepts can be applied to databases for better organization and efficiency.

• Encapsulation: Data and methods are encapsulated within classes to ensure data integrity.

• Inheritance: Tables can inherit properties and methods from other tables, reducing redundancy.

• Polymorphism: Different tables can have different implementations of the same method.

• Abstraction: Complex database structures can be abstracted into simpler, more manageable entities.

Database testing is the process of verifying the data stored in a database and ensuring its accuracy, completeness, and security.

• It involves testing the database schema, data integrity, and performance.

• Test cases are designed to check for data consistency, accuracy, and completeness.

• Security testing is also performed to ensure that the database is protected from unauthorized access.

• Examples of database testing tools include SQLUnit, DbUnit, and JMeter.

• Database testing is impo...read more

Factorial program using class syntax explained with examples.

• Factorial is the product of all positive integers up to a given number.

• Class syntax is used to define a blueprint for creating objects.

• Example: class Factorial { def fact(n): return 1 if n == 0 else n * fact(n-1) }

• Example: f = Factorial(); print(f.fact(5)) # Output: 120

Regression is the process of testing changes made to a software application to ensure that previously working functionality still works.

• Regression testing is done to ensure that new changes or updates to a software application do not negatively impact previously working functionality.

• It involves re-executing test cases that were previously run to ensure that they still pass.

• Regression testing can be done manually or through automation tools.

• Examples of regression testing incl...read more

Agile is a project management methodology that emphasizes flexibility, collaboration, and continuous improvement.

• Agile values individuals and interactions over processes and tools

• It emphasizes working software over comprehensive documentation

• Agile involves frequent iterations and feedback loops

• Scrum and Kanban are popular frameworks for implementing agile

• Agile is used in software development, but can be applied to other industries

Site quality and domain authority are important for SEO as they impact search engine rankings and user trust.

• Site quality refers to the overall user experience, including website design, content quality, and functionality.

• Domain authority is a measure of a website's credibility and trustworthiness based on factors such as backlinks and content relevance.

• Search engines prioritize high-quality sites with strong domain authority in their rankings, as they are seen as more valuab...read more

Code to print palindrome numbers from 1 to 100

• Loop through numbers 1 to 100

• Convert each number to string and check if it's equal to its reverse

• If yes, print the number

Improving site authority requires a combination of on-page and off-page optimization techniques.

• Create high-quality, shareable content that attracts backlinks from authoritative websites.

• Optimize website structure and navigation to improve user experience and reduce bounce rates.

• Build a strong social media presence to increase brand awareness and drive traffic to the site.

• Implement technical SEO best practices, such as optimizing page speed and mobile responsiveness.

• Monitor a...read more

td and tr are HTML tags used for table creation. td represents a table cell and tr represents a table row.

• td is used to define a single cell within a table row

• tr is used to define a row within a table

• td must be placed inside a tr tag

• tr can contain multiple td tags

• td can have attributes such as colspan and rowspan to span multiple cells or rows

Testing is the process of evaluating a system or application to identify defects or errors.

• Testing involves executing a system or application to find bugs or issues.

• It ensures that the software meets the specified requirements and works as expected.

• Types of testing include functional, non-functional, manual, and automated testing.

• Examples of testing tools include Selenium, JUnit, and Postman.

A class is a blueprint for creating objects, while an object is an instance of a class.

• A class defines the properties and behaviors of objects.

• An object is a specific instance of a class.

• Classes are used to create objects in object-oriented programming.

• Objects can interact with each other by calling methods defined in their class.

• Example: Class 'Car' defines properties like 'color' and 'model', while object 'myCar' is an instance of the 'Car' class with specific values for th...read more

Inheritance is a mechanism in object-oriented programming where a class inherits properties and behaviors from another class.

• Allows a class to inherit properties and behaviors from another class

• Promotes code reusability and reduces redundancy

• Creates a parent-child relationship between classes

• Derived class can access members of the base class

• Example: Class B inherits from Class A, B can use methods and variables of A

A program to print prime numbers

• Iterate through numbers and check if each number is prime

• A prime number is only divisible by 1 and itself

• Start checking from 2 onwards

• Optimization: Only check up to square root of the number

Implement a program to find the second largest element in an array of integers.

• Iterate through the array and keep track of the largest and second largest elements.

• Handle edge cases like when the array has less than 2 elements.

• Consider sorting the array and returning the second last element for a simpler solution.

Polymorphism is the ability of a function or method to behave differently based on the object it is acting upon.

• Polymorphism allows objects of different classes to be treated as objects of a common superclass.

• It enables a single interface to be used for different data types.

• Examples include method overloading and method overriding in object-oriented programming.

Loop through numbers and print the even ones.

• Use a loop to iterate through numbers

• Check if each number is even using a modulo operation

• Print the even numbers

For loop is used for iterating over a collection of items or executing a block of code a specific number of times.

• For loop syntax: for(initialization; condition; increment/decrement) { // code to be executed }

• Can be used with arrays to iterate over each element: for(int i=0; i

• Can be used to repeat a block of code a specific number of times: for(int i=0; i<5; i++) { // code to be repeated }

Function syntax is the structure and format of a function in a programming language.

• Function name followed by parentheses and parameters

• Code block enclosed in curly braces

• Return statement to output a value

• Example: function add(a, b) { return a + b; }

• Example: function greet(name) { console.log('Hello, ' + name + '!'); }