When implementing indexing, what factors should be considered to mitigate the impact on database write performance?

  • Selective indexing
  • Index maintenance strategy
  • Using index-only scans
  • Increasing index size
When implementing indexing, factors to consider for mitigating the impact on write performance include selective indexing (indexing only the columns that are frequently queried), choosing an appropriate index maintenance strategy (e.g., periodic maintenance rather than immediate updates), and using index-only scans to reduce disk I/O during reads. Increasing the index size can have a negative impact on write performance, so it should be done judiciously.

To override ESLint rules for specific files or directories, you can create a .eslintignore or ______ file with the patterns of the files or directories to be excluded.

  • .eslintrc.js
  • .eslintignore
  • .eslintconfig
  • .eslintexclude
To override ESLint rules for specific files or directories, you can create a .eslintignore file with patterns of the files or directories to be excluded from ESLint linting. The other options are not used for this purpose.

Which of the following events is emitted when data is available to read from a readable stream?

  • data
  • readable
  • onData
  • available
In Node.js, the 'data' event is emitted when data is available to read from a readable stream. This event allows you to consume the data as it becomes available. The other options are not standard events for this purpose.

How can optimizing database queries significantly reduce the response time of an application?

  • Optimizing queries can make the code more readable but doesn't affect response time.
  • Optimizing queries can reduce the number of database calls and minimize data retrieval, improving response time.
  • Optimizing queries doesn't impact response time; it only reduces server memory usage.
  • Optimizing queries can speed up server initialization but has no effect on response time.
Optimizing database queries can significantly reduce response time by minimizing the number of database calls, reducing data retrieval, and improving the efficiency of data fetching, ultimately leading to faster responses. The other options either misrepresent the impact of query optimization or provide irrelevant information.

When performing file operations using the fs module, handling ______ errors is crucial to ensure data integrity.

  • synchronous
  • asynchronous
  • promise
  • event
When working with file operations in Node.js using the fs module, handling asynchronous errors is crucial. Asynchronous file operations can fail due to various reasons such as file not found, permission issues, or disk full errors. Proper error handling ensures data integrity and prevents unexpected crashes in your application.

How can you define optional route parameters in Express.js?

  • Enclose parameters in square brackets [param]
  • Use the optional keyword before the parameter
  • Use the ? symbol after the parameter
  • Wrap parameters in parentheses (param)
In Express.js, you can define optional route parameters by using the ? symbol after the parameter name, like /route/:param?. This makes the parameter optional, allowing it to match both routes with and without that parameter. The other options do not represent the correct way to define optional route parameters in Express.js.

You are creating a build for a production environment and realize that some of the devDependencies are being included in the build, causing it to be bulkier. What steps would you take to rectify this?

  • Manually remove devDependencies from package.json
  • Use Webpack to exclude devDependencies
  • Use the npm prune --production command
  • Upgrade all devDependencies to their latest versions
To rectify this issue, you should use the npm prune --production command. This command removes unnecessary devDependencies from your node_modules directory, ensuring that only production dependencies are included in the build. Options (1) and (4) are not recommended because manually removing or upgrading devDependencies can be error-prone. Option (2) doesn't directly address the issue, and Webpack is typically used for bundling rather than dependency management.

You are developing an e-commerce application where multiple API calls are made to fetch product details. How can you efficiently handle multiple Promises to ensure that even if one fails, others continue execution?

  • Promise.allSettled()
  • Promise.race()
  • Promise.all()
  • Promise.any()
In this scenario, you can efficiently handle multiple Promises using Promise.allSettled(). This method returns an array of results for all Promises, allowing you to handle both resolved and rejected Promises without stopping the execution of others. Promise.race() would stop execution on the first rejection, Promise.all() requires all to resolve, and Promise.any() stops on the first resolution.

How can developers specify the version of their package when publishing to the NPM registry?

  • npm set-version
  • npm version
  • npm update
  • npm publish --version
Developers can specify the version of their package when publishing to the NPM registry using the npm version command followed by the desired version number, e.g., npm version 1.0.0. The other options do not perform this specific task.

Which of the following is a use case for the rest operator in function parameters?

  • Collecting multiple arguments into an array
  • Spreading an array into multiple arguments
  • Creating a shallow copy of an array
  • Combining two arrays into one
The primary use case for the rest operator in function parameters is to collect multiple arguments into an array. It allows a function to accept a variable number of arguments and access them as an array. The other options are not the intended use of the rest operator in this context.