TCS Mern Full Stack Developer Interview Questions and Answers

Q1. What is differnce between class and functional component
Ans. 
Class components are ES6 classes that extend from React.Component and have a render method, while functional components are simple functions that return JSX.
• Class components are more feature-rich and have access to lifecycle methods like componentDidMount, componentDidUpdate, etc.

• Functional components are simpler and easier to read, especially for simple UI components.

• Functional components can use React Hooks to manage...read more
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Q2. Write a basic function component
Ans. 
A basic function component in React
• Create a function component using the 'function' keyword

• Return JSX elements within the component function

• Example: const MyComponent = () => { return

  Hello World!
  ; }
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Q1. What is virtual DOM?
Ans. 
Virtual DOM is a lightweight copy of the actual DOM that allows for efficient updates and rendering in web applications.
• Virtual DOM is a concept used in frameworks like React to improve performance by minimizing direct manipulation of the actual DOM.

• When changes are made to the virtual DOM, a comparison is done with the actual DOM to identify the minimal number of updates needed.

• This approach reduces the number of DOM ...read more
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Q2. What is foriegn Key SQL?
Ans. 
Foreign key in SQL is a field in a table that is a primary key in another table, establishing a relationship between the two tables.
• A foreign key constraint ensures referential integrity between two related tables.

• It helps maintain consistency and avoid orphan records.

• Example: In a database with tables 'orders' and 'customers', the 'customer_id' in 'orders' table can be a foreign key referencing the 'id' column in 'cus
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Q1. What is props
Ans. 
Props are read-only properties that are passed from a parent component to a child component in React.
• Props allow data to be passed down the component tree.

• Props are immutable and cannot be changed by the child component.

• Props are accessed in the child component using this.props.
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Q2. What is Good feedback you ever got in during you development period.
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Q1. What is error handling middleware?
Ans. 
Error handling middleware is a function that processes errors in an Express application.
• Error handling middleware is defined with four parameters: err, req, res, and next.

• It is used to catch errors that occur during the execution of route handlers or other middleware functions.

• It is typically defined at the end of the middleware chain with app.use() and has a signature like (err, req, res, next) => {...}.

• Example: app.u...read more
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Trips for cracking interview

Q1. For example how to replay for all questions
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Q2. Different questions for all types
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Q3. Interviews easily cracking trips
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Q4. How to get good job in software
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Q5. How to get job
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Q1. Do you have an internship opportunity for a Full-stack Developer(Fresher)?
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Q1. Is the internship for a full-stack developer paid?
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Q1. How many years is the internship for a full-stack Developer?
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Q1. Javascript questions were mainly there like closures , currying Objects and promises , then they started with React
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Q2. In react they asked about hooks, difference between props and state, version , useMemo , axios working , microservices
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Q1. Why do u want to join us , u already holding an offer
Ans. 
I am drawn to your company's innovative projects and collaborative work environment.
• I am impressed by the cutting-edge technologies and projects your company is working on.

• I value the opportunity to work in a collaborative and supportive team environment.

• I believe that joining your company will provide me with the chance to further develop my skills and contribute meaningfully to impactful projects.
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Q2. How do u prioritize your task
Ans. 
I prioritize tasks based on deadlines, importance, and dependencies.
• I create a list of all tasks and categorize them based on deadlines.

• I identify tasks that are critical to the project's success and prioritize them accordingly.

• I consider dependencies between tasks and prioritize those that are dependent on others being completed first.

• I regularly reassess priorities and adjust as needed based on changing circumstances...read more
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