200+ Developer Interview Questions and Answers

React is called unidirectional because data flows in one direction, from parent to child components.

• React's unidirectional data flow means that data is passed down from parent components to child components, but not the other way around.

• While callbacks can be used to send data back to parents from child components, this does not change the overall unidirectional flow of data in React.

• This one-way data flow helps to maintain a clear and predictable data flow in React applicati...read more

Upgrading software or systems is essential for improved performance, security, and access to new features.

• Security Vulnerabilities: If a version has known security issues, upgrading is crucial. For example, upgrading from an outdated framework to patch vulnerabilities.

• Performance Improvements: New versions often come with optimizations. For instance, upgrading a database system can lead to faster query performance.

• New Features: If a new version introduces features that can en...read more

M scripting is a programming language used for data manipulation and analysis. Based workspace is a feature in M scripting for managing data and variables.

• M scripting is a programming language used in Power Query for data transformation and manipulation.

• Based workspace in M scripting allows users to manage data and variables in a structured manner.

• Examples of M scripting functions include Table.AddColumn, Table.TransformColumns, and List.Transform.

OOPs stands for Object-Oriented Programming while POPs stands for Procedure-Oriented Programming. Encapsulation is the concept of bundling data and methods that operate on the data into a single unit. Polymorphism refers to the ability of a single function or method to operate on different types of data.

• OOPs focuses on objects and classes, allowing for better organization and reusability of code.

• POPs focuses on procedures and functions, which can lead to less organized and le...read more

A two-way switch is a device that can be used to control a single electrical circuit from two different locations.

• A two-way switch typically has three terminals: a common terminal and two traveler terminals.

• The common terminal is connected to the power source, while the traveler terminals are connected to the load.

• The switch can be toggled between the two traveler terminals to control the circuit from different locations.

The interview question involves coding questions related to counting words in a sentence, determining if a linked list is circular, and creating a star pattern.

• To count the number of words in a sentence, split the sentence by spaces and count the number of resulting elements.

• To determine if a linked list is circular, use two pointers moving at different speeds - if they meet, the list is circular.

• To create a star pattern, use nested loops to print the desired pattern of stars...read more

Call, apply, and bind are methods used to manipulate the value of 'this' in JavaScript functions.

• Call and apply are used to invoke a function with a specific 'this' value and arguments passed as an array or list respectively.

• Bind returns a new function with a specific 'this' value and any arguments passed as a list.

• Example: myFunction.call(thisValue, arg1, arg2); myFunction.apply(thisValue, [arg1, arg2]); myFunction.bind(thisValue, arg1, arg2);

Composition is a strong relationship where the child object cannot exist without the parent object. Aggregation is a weak relationship where the child object can exist independently.

• Composition is a 'has-a' relationship, where the parent object owns the child object.

• Aggregation is a 'has-a' relationship, where the child object is a part of the parent object.

• In composition, the child object's lifetime is managed by the parent object.

• In aggregation, the child object's lifetime ...read more

Props and cons are not specific terms in JavaScript. Did you mean pros and cons?

• Pros: flexibility, easy to learn, wide range of applications

• Cons: can be slow, can be difficult to debug, can have security vulnerabilities

Defiance refers to resistance or disobedience, while first and default are different spellings of words with distinct meanings.

• Defiance implies a refusal to comply with authority or rules.

• First refers to the initial or primary thing in a sequence or list.

• Default refers to a pre-set value or option that is used when no other choice is made.

• Examples: Defiance - civil disobedience, First - first place in a race, Default - default font in a word processor.

Closures are functions that have access to variables in their outer scope, even after the outer function has returned.

• Closures are created when a function is defined inside another function.

• The inner function has access to the outer function's variables, even after the outer function has returned.

• Closures can be used to create private variables and methods in JavaScript.

• Example: function outer() { var x = 10; function inner() { console.log(x); } return inner; } var closure = ...read more

The 2 egg problem is a classic puzzle about minimizing egg drops to find the highest safe floor in a building.

• Use two eggs to minimize the number of drops needed.

• Start dropping from a certain floor and increase the drop floor incrementally.

• If the first egg breaks, use the second egg to check each floor below the last drop.

I have learned multiple programming languages including Java, Python, and C++.

• Java

• Python

• C++

Join queries are used to combine data from multiple tables based on a common column.

• Join queries are used when data is spread across multiple tables and needs to be combined for analysis.

• They are useful for retrieving data from related tables, such as customer orders and order details.

• Join queries can be used to filter data based on specific criteria, such as only retrieving orders from a certain date range.

• There are different types of join queries, such as inner join, left j...read more

React is a JavaScript library for building user interfaces, known for its component-based architecture and virtual DOM.

• React uses a virtual DOM for better performance by only updating the necessary parts of the actual DOM.

• React follows a component-based architecture, making it easier to reuse code and maintain.

• React allows developers to write JSX, a syntax extension that resembles HTML, to define the UI components.

• React is more focused on the view layer of the application, wh...read more

HashMap is a data structure that stores key-value pairs and provides constant time complexity for basic operations.

• HashMap is implemented using an array of linked lists or a balanced tree.

• It allows null values and at most one null key.

• The put() method is used to insert a key-value pair into the HashMap.

• The get() method is used to retrieve the value associated with a given key.

• Example: HashMap<String, Integer> map = new HashMap<>();

Code to transpose a matrix

• Iterate through rows and columns of the matrix

• Swap the elements at (i,j) and (j,i) positions

• Return the transposed matrix

When a job abends, it indicates an abnormal termination, requiring specific steps to diagnose and resolve the issue.

• Identify the error message: Check logs for specific error codes or messages that indicate the cause of the abend.

• Analyze job dependencies: Determine if other jobs or processes affected the job's execution.

• Review recent changes: Look for any recent code changes or configuration updates that might have led to the abend.

• Restart the job: If the issue is transient, a...read more

The 4 pillars of C++ are Abstraction, Encapsulation, Inheritance, and Polymorphism.

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

• Encapsulation: Binding data and functions together to prevent external interference.

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

• Polymorphism: Using a single interface to represent multiple types of objects.

Program to reverse a string without using inbuilt function

• Create an empty string to store the reversed string

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

• Return the reversed string

There are four types of joining in SQL: Inner Join, Left Join, Right Join, and Full Join.

• Inner Join returns only the matching rows from both tables.

• Left Join returns all the rows from the left table and matching rows from the right table.

• Right Join returns all the rows from the right table and matching rows from the left table.

• Full Join returns all the rows from both tables, with NULL values in the columns where there is no match.

• Examples: Inner Join - SELECT * FROM table1 IN...read more

Hooks are functions that allow you to use state and other React features without writing a class.

• Hooks were introduced in React 16.8

• They allow you to reuse stateful logic

• useState is a hook that allows you to add state to a functional component

• useEffect is a hook that allows you to perform side effects in a functional component

• useContext is a hook that allows you to consume a context in a functional component

My aim is to continuously improve my skills and knowledge in software development while contributing to the success of the company.

• To become a proficient developer

• To learn new technologies and programming languages

• To contribute to the success of the company

• To work collaboratively with other developers

• To deliver high-quality software products

Yes, integration between SAP DataSphere and SAC is possible.

• SAP DataSphere can be integrated with SAP Analytics Cloud (SAC) to enable data sharing and analysis.

• Integration allows users to access and analyze data from SAP DataSphere within SAC.

• Data can be imported from SAP DataSphere into SAC for further analysis and visualization.

• Integration enables real-time data updates and synchronization between SAP DataSphere and SAC.

• Users can create dashboards, reports, and visualizatio...read more

Java is an object-oriented, platform-independent language, while C is a procedural language with low-level memory access.

• Java is platform-independent due to the Java Virtual Machine (JVM), while C is platform-dependent and compiled directly to machine code.

• Java supports automatic garbage collection, whereas C requires manual memory management using malloc() and free().

• Java is strictly object-oriented, meaning everything is an object, while C is a procedural language that supp...read more

ABAP Dictionary is a central repository for data definitions used in SAP applications. ALV report events are user actions in ALV grid. OOPs ABAP is object-oriented programming in ABAP.

• ABAP Dictionary is used to define and manage data definitions in SAP applications

• ALV report events include user actions like clicking on a row or column header

• OOPs ABAP allows for object-oriented programming concepts like classes and inheritance

RPG3 and RPG4 are different versions of the RPG programming language. RPG3 is an older version, while RPG4 is a newer and more advanced version.

• RPG3 is the third version of the RPG programming language, while RPG4 is the fourth version.

• RPG4 introduced many new features and enhancements compared to RPG3.

• RPG4 supports free-format coding, which allows for more flexibility and readability in code.

• RPG4 has improved support for SQL integration, making it easier to work with databas...read more