20+ Micro Labs Interview Questions and Answers

Questions on OOPs concepts, inheritance, mutable in Java, memory allocation functions, and difference between delete and truncate.

• Inheritance is a mechanism in OOPs where a class can inherit properties and methods from another class.

• Java supports single inheritance but not multiple inheritance.

• Mutable in Java refers to objects whose state can be modified after creation.

• Malloc and calloc are memory allocation functions in C programming.

• Delete is a SQL command used to remove ro...read more

Difference between C and C++, pointer definition and usage

• C++ is an object-oriented language while C is procedural

• C++ supports function overloading and templates while C does not

• Pointers are variables that store memory addresses

• Pointers are used for dynamic memory allocation and passing parameters by reference

• Example: int *ptr; // declares a pointer to an integer variable

Java is a high-level programming language known for its portability, security, and versatility.

• Java is platform-independent, meaning it can run on any device with a Java Virtual Machine (JVM).

• It is known for its strong security features, such as automatic memory management and built-in exception handling.

• Java is versatile, with a wide range of applications including web development, mobile apps, and enterprise software.

• The language is object-oriented, making it easier to orga...read more

A heap is a data structure used to store and manage dynamically allocated memory.

• A heap is a region of memory that is managed by the operating system.

• It is used to store data that is allocated dynamically at runtime.

• The base structure used to build a heap is typically a binary tree.

• Heap operations include allocating and deallocating memory, and sorting data.

• Examples of languages that use heaps include C, C++, and Java.

Java is called object oriented programming language because it is designed to use objects and classes to organize and structure code.

• Java is based on the concept of objects, which are instances of classes

• Classes define the properties and behaviors of objects

• Java supports encapsulation, inheritance, and polymorphism, which are key features of object-oriented programming

• Example: A Java program for a bank might have classes for customers, accounts, and transactions

• Objects of the...read more

Pega is different from conventional programming because it is a low-code platform that allows for rapid development and easy customization.

• Pega uses a visual development environment with drag-and-drop components, making it easier for non-programmers to create applications.

• Pega's rules-based architecture allows for quick changes and updates without extensive coding.

• Pega focuses on business processes and rules rather than traditional coding, making it more aligned with business...read more

Code to check if a number is a palindrome or not.

• Convert the number to a string to easily check for palindrome

• Reverse the string and compare it with the original string to check for palindrome

• If the reversed string is equal to the original string, then the number is a palindrome

Program to reverse a string without using in-built functions

• Create a new empty string to store the reversed string

• Iterate through the original string from end to start and append each character to the new string

• Print or return the reversed string

I am proficient in multiple programming languages including Java, Python, and C++.

• Proficient in Java, Python, and C++

• Experience with web development languages such as HTML, CSS, and JavaScript

• Familiarity with scripting languages like Bash and PowerShell

• Knowledge of database languages like SQL and NoSQL

• Experience with version control systems like Git

Object oriented programming language is a programming paradigm that uses objects to represent data and methods.

• It focuses on encapsulation, inheritance, and polymorphism.

• Examples include Java, C++, Python, and Ruby.

• Objects have attributes (data) and methods (functions).

The types of processes in data analysis include data collection, data cleaning, data transformation, data modeling, and data visualization.

• Data collection involves gathering raw data from various sources.

• Data cleaning is the process of identifying and correcting errors in the data.

• Data transformation involves converting raw data into a format suitable for analysis.

• Data modeling is the process of creating mathematical models to make predictions or decisions based on the data.

• D...read more

Code to blink red and blue bulb alternatively

• Use a loop to alternate between turning on and off the red and blue bulbs

• Use a delay function to control the timing of the blinking

• Toggle the state of the bulbs using a boolean variable

To reverse a string, iterate through it in reverse order and append each character to a new string.

• Create an empty string to store the reversed string

• Iterate through the original string in reverse order

• Append each character to the new string

• Return the new string

A foreign key is a column or set of columns in a database table that refers to the primary key of another table.

• It establishes a link between two tables in a relational database.

• It ensures referential integrity between the tables.

• It can be used to join tables in a query.

• Example: CustomerID in Orders table refers to the CustomerID in Customers table.

There are various rules in Pega such as validation rules, decision rules, data transform rules, etc.

• Validation rules ensure data entered by users meets specified criteria

• Decision rules determine the logic for decision-making in the application

• Data transform rules define how data is transformed from one format to another

• UI rules control the appearance and behavior of user interfaces

• Integration rules define how the application interacts with external systems

OOPM stands for Object-Oriented Programming Methodology. Network topologies refer to the physical or logical layout of a network.

• OOPM is a programming paradigm that focuses on objects and their interactions.

• It emphasizes encapsulation, inheritance, and polymorphism.

• Examples of OOPM languages include Java, C++, and Python.

• Network topologies include bus, star, ring, mesh, and hybrid.

• They determine how devices are connected and communicate with each other.

• Each topology has its o...read more

Comparison between PHP and Python

• PHP is a server-side scripting language while Python is a general-purpose language

• PHP is faster for web development while Python is better for data analysis and machine learning

• PHP has a larger community and more resources available while Python has a simpler syntax and is easier to learn

• PHP is used for popular CMS like WordPress while Python is used for scientific computing and AI applications

Method overloading is when multiple methods in a class have the same name but different parameters.

• Allows a class to have multiple methods with the same name but different parameters

• Parameters can differ in number, type, or order

• Compile-time polymorphism

• Example: void print(int a), void print(int a, int b)

Inheritance is a concept in object-oriented programming where a class can inherit attributes and methods from another class.

• Allows a class to inherit attributes and methods from another class

• Promotes code reusability and reduces redundancy

• Creates a parent-child relationship between classes

• Derived class can access all public and protected members of the base class

• Example: Class 'Car' can inherit from class 'Vehicle'

Set and Map are both data structures in Java, but Set stores unique elements while Map stores key-value pairs.

• Set does not allow duplicate elements, while Map allows duplicate values but not duplicate keys.

• In Set, elements are stored in an unordered manner, while in Map, key-value pairs are stored.

• Example: Set set = new HashSet<>(); Map map = new HashMap<>();

Developed a web-based inventory management system for a retail company

• Used Java and Spring framework for backend development

• Implemented responsive design using HTML, CSS, and JavaScript for frontend

• Integrated with third-party APIs for payment processing and order tracking

Even and odd code in Python separates numbers into even and odd categories.

• Create two empty lists, one for even numbers and one for odd numbers.

• Iterate through the input list of numbers and append each number to the appropriate list based on its parity.

• Return the two lists containing even and odd numbers respectively.

Pointers are variables that store memory addresses of other variables or functions.

• Pointers allow for dynamic memory allocation and manipulation.

• They are commonly used in programming languages like C and C++.

• Example: int *ptr; // declares a pointer variable that can store the memory address of an integer variable

• Dereferencing a pointer means accessing the value stored at the memory address it points to.

• Example: int x = 5; int *ptr = &x; // assigns the memory address of x to p...read more

Java 8 introduced several new features including lambda expressions, functional interfaces, streams, and default methods.

• Lambda expressions allow you to pass functionality as an argument to a method.

• Functional interfaces have a single abstract method and can be used with lambda expressions.

• Streams provide a way to work with sequences of elements efficiently.

• Default methods allow interfaces to have method implementations.

• Example: Lambda expression - (a, b) -> a + b

• Example: Fun...read more

Query to find leap year in SQL

• Use modulo operator (%) to check if year is divisible by 4

• If year is divisible by 100, also check if it is divisible by 400

• Return years that meet both conditions as leap years

Inheritance is a mechanism in object-oriented programming where a new class is created by inheriting properties of an existing class.

• Inheritance allows for code reuse and promotes a hierarchical organization of classes.

• The existing class is called the superclass or parent class, while the new class is called the subclass or child class.

• The subclass inherits all the properties and methods of the superclass, and can also add new properties and methods or override existing ones....read more

Bubble sort is a simple sorting algorithm that repeatedly steps through the list, compares adjacent elements and swaps them if they are in the wrong order.

• Bubble sort is a comparison-based algorithm.

• It works by comparing each pair of adjacent elements and swapping them if they are in the wrong order.

• It has a worst-case and average-case time complexity of O(n^2).

• Example: [5, 3, 8, 4, 2] -> [3, 5, 4, 2, 8] -> [3, 4, 2, 5, 8] -> [3, 2, 4, 5, 8] -> [2, 3, 4, 5, 8]