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.
In Express.js, to serve static files, you generally use the ______ middleware.
- static
- middleware
- server
- file
In Express.js, to serve static files, you generally use the static middleware. This middleware allows you to serve files such as images, CSS, and JavaScript to clients.
Improper handling of dependencies and devDependencies can lead to larger ________ sizes when deploying an application.
- bundle
- package
- container
- memory
Improper handling of dependencies and devDependencies can lead to larger bundle sizes when deploying an application. When you include unnecessary dependencies, your application's bundle size increases, impacting load times and performance.
The Access-Control-Allow-Methods header in CORS specifies which HTTP ________ are allowed.
- methods
- verbs
- headers
- origins
The Access-Control-Allow-Methods header in CORS specifies which HTTP methods are allowed for cross-origin requests. It should include a comma-separated list of HTTP methods such as GET, POST, PUT, DELETE, etc.
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.
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.
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.
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.
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.
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 does Non-Blocking I/O facilitate the development of scalable applications in Node.js?
- It allows multiple I/O operations to be executed concurrently without blocking the main thread.
- It forces all I/O operations to be executed sequentially, which improves predictability.
- It has no impact on application scalability.
- It reduces the number of I/O operations that can be performed concurrently.
Non-Blocking I/O in Node.js enables the execution of multiple I/O operations concurrently without blocking the main thread. This concurrency is essential for developing scalable applications that can handle numerous incoming requests simultaneously.
When using the rest operator in a function’s parameters, it will collect the remaining arguments into an ______.
- Array
- Object
- String
- Argument
When using the rest operator (...) in a function's parameters, it will collect the remaining arguments into an "Array." This allows you to work with variable-length argument lists easily.