You are developing a large-scale application and notice that some modules are loading slowly. How would you optimize the loading of modules to improve the application's performance?

  • Minify and bundle all modules into a single file.
  • Use lazy loading to load modules on-demand.
  • Increase server hardware resources.
  • Reduce the number of modules.
To optimize the loading of modules in a large-scale application, you should use lazy loading (Option b). Lazy loading allows modules to be loaded only when they are needed, reducing initial load times and improving performance. Minification (Option a) is also a valid optimization technique but may not address the issue of slow initial loading. Increasing server resources (Option c) and reducing the number of modules (Option d) are not effective solutions for optimizing module loading.

You are tasked with creating an API endpoint that should respond to multiple HTTP methods (GET, POST) and have optional parameters. How would you efficiently implement this in Express.js?

  • Use app.all('/endpoint', handler)
  • Create separate route handlers for each HTTP method and parameter combination
  • Implement a single route handler and use conditional logic to handle methods and parameters
  • Define multiple endpoints for each combination of HTTP methods and parameters
In Express.js, an efficient way to handle multiple HTTP methods and optional parameters is to implement a single route handler and use conditional logic to differentiate between methods and handle optional parameters within the handler. This approach minimizes code duplication and keeps your codebase clean and maintainable. Using app.all (Option 1) would capture all HTTP methods and may lead to less control and more complex code. Separating handlers for each combination (Option 2) can result in code redundancy, making it harder to maintain. Creating multiple endpoints (Option 4) can lead to a cluttered route structure.

What considerations should be made while implementing asynchronous middleware in Express.js?

  • Asynchronous middleware should use the await keyword to ensure proper execution flow.
  • Asynchronous middleware should always return a Promise or use a callback.
  • Asynchronous middleware should not be used in Express.js as it can lead to performance issues.
  • Asynchronous middleware should use the sync keyword to ensure proper execution flow.
When implementing asynchronous middleware in Express.js, it's crucial to ensure that the middleware either returns a Promise or uses a callback to signal when it has completed its work. This is necessary to prevent premature termination of the request-response cycle and maintain proper error handling. Using await is a common approach to handling asynchronous operations.

In case a package should be uninstalled and also removed from the package.json, the ______ command should be executed.

  • npm remove
  • npm uninstall
  • npm erase
  • npm discard
To uninstall a package and also remove it from the package.json file, you should use the npm uninstall (or npm remove) command followed by the package name. This command removes both the package and its reference from package.json. The other options are not used for this specific purpose.

You are tasked with optimizing the build process for a production environment. What considerations should you make regarding the management of dependencies and devDependencies?

  • Include all dependencies in devDependencies
  • Minimize the use of dependencies
  • Exclude devDependencies in production builds
  • Always use the latest version of dependencies
In a production build, it's important to exclude devDependencies as they are typically only needed for development and testing. Including them in production builds can increase the size of the application unnecessarily. Option (2) is a good practice, but not directly related to managing dependencies for production. Option (1) is incorrect as including all dependencies in devDependencies is not a best practice for production builds. Option (4) is risky as it may introduce compatibility issues.

How can you create a buffer instance in Node.js?

  • new Buffer(10)
  • Buffer.alloc(10)
  • createBuffer(10)
  • buffer.create(10)
In Node.js, you can create a buffer instance using the Buffer.alloc(size) method, where size is the desired size of the buffer in bytes. The new Buffer() constructor is deprecated, and the other options are not valid ways to create a buffer in Node.js.

In which scenario is a full-text search most appropriately used?

  • Searching for specific keywords within a large body of text
  • Searching for structured data in a database
  • Searching for filenames in a file system
  • Searching for numerical values in a spreadsheet
Full-text search is most appropriately used when searching for specific keywords within a large body of text, such as searching for documents or articles containing certain words or phrases. It allows for complex text-based queries, making it ideal for content-heavy applications.

To add an item to the beginning of an array in JavaScript, you can use the ______ method.

  • push
  • unshift
  • append
  • insert
In JavaScript, you can use the unshift method to add an item to the beginning of an array. The push method adds an item to the end of an array. append and insert are not native array methods in JavaScript.

What is the primary purpose of using an ORM (Object-Relational Mapper) like Sequelize in a project?

  • To facilitate database interactions by mapping JavaScript objects to database tables
  • To create user interfaces for web applications
  • To optimize code for better performance
  • To secure API endpoints
The primary purpose of using an Object-Relational Mapper (ORM) like Sequelize is to facilitate database interactions by mapping JavaScript objects to database tables. It abstracts the underlying database, making it easier to work with databases and reducing the need for writing raw SQL queries. The other options are not the primary purposes of an ORM.

n CRUD operations, which operation is used to modify existing data?

  • Create
  • Read
  • Update
  • Delete
The Update operation in CRUD (Create, Read, Update, Delete) operations is used to modify existing data in the system. It allows you to make changes to existing records.