Which file is created by default when you run the npm init command in a Node.js project?
- package.json
- index.js
- node_modules
- app.js
When you run npm init in a Node.js project, it creates a package.json file by default. This file is used to manage project dependencies, scripts, and other project-related information. The other options are not created by npm init itself.
What is the primary purpose of the Buffer class in Node.js?
- To handle HTTP requests
- To manipulate JavaScript objects
- To work with binary data
- To create web pages
The primary purpose of the Buffer class in Node.js is to work with binary data, allowing you to read from or write to streams, interact with file systems, and deal with raw data. It is especially useful in scenarios where you need to work with data in a way that JavaScript's string handling is not suitable, such as when dealing with file I/O or network communication.
You are developing an e-commerce application requiring complex transactions and relationships between entities, such as users, orders, and products. What type of database would be most appropriate, and what considerations should you have regarding normalization and indexing?
- Key-Value Database
- Document Database
- Relational Database
- Column-family Database
A relational database would be most appropriate for complex transactions and entity relationships in an e-commerce application. Considerations include normalization to eliminate data redundancy and indexing for efficient querying. Proper indexing strategies can significantly improve query performance in relational databases.
When implementing a transform stream, which method should be implemented to handle the transformation of chunks?
- _transform
- _read
- _write
- _pipe
When implementing a transform stream in Node.js, you should implement the _transform method. This method receives input data in chunks and allows you to process and transform the data before passing it downstream. The other options are not specific to transform streams.
How can you set up ESLint to lint TypeScript files in a project?
- npm install --save-dev eslint @typescript-eslint/parser @typescript-eslint/eslint-plugin
- npm install --global eslint
- npm install --save-dev eslint
- npm install --save-dev eslint-plugin-typescript
To set up ESLint for TypeScript, you need to install eslint, @typescript-eslint/parser, and @typescript-eslint/eslint-plugin as dev dependencies. This combination allows ESLint to parse and analyze TypeScript code. The other options do not cover TypeScript-specific linting.
When creating a custom lifecycle script, the ______ event can be used to perform tasks after the main event has completed.
- post
- after
- complete
- finish
When creating a custom lifecycle script in Node.js, you can use the post event to perform tasks after the main event has completed. This allows you to extend or customize the behavior of existing npm lifecycle events. The other options do not represent standard event names in npm scripts.
The fs module provides both synchronous and asynchronous methods, identified by the ______ suffix for synchronous methods.
- async
- sync
- synchronous
- await
In the fs module of Node.js, synchronous methods are identified by the Sync suffix. For example, fs.readFileSync is a synchronous method for reading files, whereas asynchronous methods do not have this suffix.
Which testing framework is commonly used for writing tests in Node.js applications?
- Mocha
- Jasmine
- Jest
- Chai
Jest is a popular testing framework commonly used for writing tests in Node.js applications. It provides a comprehensive toolset for testing and is known for its simplicity and speed.
What is the default behavior of Express when an error occurs in a middleware?
- Continue processing the request
- Send a 500 Internal Server Error response
- Stop processing and close the connection
- Return a 404 Not Found response
The default behavior of Express when an error occurs in a middleware is to send a 500 Internal Server Error response. This ensures that the client receives an appropriate error response when something goes wrong in the middleware chain. The other options describe different behaviors that do not occur by default.
Which JavaScript expression uses the rest operator?
- function myFunction(a, b, ...rest)
- const [x, y, ...rest] = arr;
- const {x, y, ...rest} = obj;
- const rest = [a, b, ...c];
The rest operator (...) is used in function parameters to collect all remaining arguments into an array. In the example function myFunction(a, b, ...rest), the ...rest collects any additional arguments passed to the function into an array named rest.