Which type of index is most suitable for searching through text-based content in a database?
- Full-Text Index
- B-Tree Index
- Hash Index
- Bitmap Index
Full-Text Index is the most suitable index type for searching through text-based content in a database. It is optimized for text search queries, allowing for efficient searching of words and phrases within text fields. B-Tree, Hash, and Bitmap indexes are more appropriate for different types of data and queries.
When chaining Promises, returning a non-Promise value from a .then() handler will cause the next .then() in the chain to receive a Promise resolved with that ________.
- Error
- Value
- Promise
- Rejection
When you return a non-Promise value (a regular value) from a .then() handler, the next .then() in the chain will receive a Promise that is resolved with that value. This allows you to pass values between Promise chain steps.
What is the outcome of using closures regarding variable scope and lifetime in JavaScript?
- Variables declared in a closure have global scope.
- Variables declared in a closure are accessible only within the closure itself.
- Variables declared in a closure have the same scope as variables declared in the outer function.
- Variables declared in a closure have function scope.
Closures in JavaScript have function scope, meaning variables declared within a closure are accessible only within that closure. They do not have global scope and are not directly accessible from outside the closure.
How can you access environment variables in a Node.js application using the process object?
- process.env.MY_VARIABLE
- Node.env.get("MY_VARIABLE")
- global.MY_VARIABLE
- env.process.MY_VARIABLE
In a Node.js application, you can access environment variables using process.env.MY_VARIABLE. The process object provides access to environment variables, and you access them using dot notation. The other options are incorrect syntax or reference non-existent objects.
To avoid callback hell while working with the fs module, you can use the ______ API, which returns promises.
- async
- await
- util.promisify
- Promise
To avoid callback hell when working with the fs module in Node.js, you can use the util.promisify API, which converts callback-based functions into promise-based functions. This allows you to work with promises and async/await syntax, improving code readability and maintainability.
Which of the following is true regarding the 'let' keyword in ES6+?
- let variables are hoisted to the top of their scope.
- let variables are block-scoped.
- let variables are globally scoped.
- let variables cannot be reassigned after declaration.
In ES6+, the let keyword is used to declare variables that are block-scoped, meaning they are limited to the block in which they are declared. Unlike var, let variables are not hoisted to the top of their scope. They can also be reassigned after declaration.
How can you handle errors in middleware in Express.js?
- Errors in middleware are automatically handled by Express.js and sent as a default error response.
- Use the next() function with an error object to pass it to an error handling middleware.
- Errors in middleware should be caught with a try...catch block inside the middleware function.
- Express.js does not support error handling in middleware.
In Express.js, errors in middleware can be handled by calling next(error) to pass the error to an error handling middleware. This allows for centralized error handling.
How can middleware functions modify the request and response objects in Express.js?
- Middleware functions can modify request and response objects directly.
- Middleware functions cannot modify request and response objects in Express.js.
- Middleware functions can only modify the request object, not the response object.
- Middleware functions can only modify the response object, not the request object.
Middleware functions in Express.js have access to the request and response objects, and they can modify these objects directly. This allows them to add, modify, or remove properties and headers, which is useful for various purposes like authentication, logging, and data transformation.
What happens if you omit the break statement in a switch statement in JavaScript?
- The program continues to execute the code in subsequent cases until it encounters a break statement or the end of the switch statement.
- An error is thrown, and the program crashes.
- The switch statement will exit immediately.
- The program ignores the switch statement entirely.
If you omit the break statement in a switch statement in JavaScript, the program will continue to execute the code in subsequent cases until it encounters a break statement or reaches the end of the switch statement. This behavior is known as "fall-through." The other options do not accurately describe the behavior of omitting the break statement.
You are building a content management system where the data structure is not uniform and may evolve over time. Which type of database would you choose, and what considerations should you have regarding schema design and querying efficiency?
- Graph Database
- NoSQL Database
- Relational Database
- Object-oriented Database
In this scenario, a NoSQL database would be the most suitable choice due to its flexibility in handling unstructured and evolving data. Considerations involve schema-less design, allowing data to change without strict schema constraints, and optimizing querying efficiency through appropriate indexing and data modeling.