What does the 'major' number in a semantic versioning format (e.g. 1.2.3) typically represent?
- Major changes
- Minor changes
- Patch changes
- Build number
In semantic versioning (SemVer), the 'major' number represents significant changes that are not backwards-compatible. This means that if the 'major' version number increases, it indicates that there have been substantial changes in the software that may break compatibility with previous versions.
What is the primary purpose of using modules in JavaScript?
- Code organization and encapsulation
- Enhancing performance
- Creating user interfaces
- Managing database connections
The primary purpose of using modules in JavaScript is code organization and encapsulation. Modules help break down large programs into smaller, manageable pieces of code, making it easier to maintain and collaborate on projects. While modules can have other benefits, such as enhancing performance, their main role is to structure and organize code.
How can you prevent a specific package from being updated when running npm update?
- Use the "npm lock" command to lock the package's version.
- Edit the package.json file to specify the exact version of the package you want.
- Run "npm update --no-save"
- Delete the package and reinstall it.
To prevent a specific package from being updated when running npm update, you can edit your project's package.json file and specify the exact version of the package you want. This ensures that the package remains at the specified version. Using "npm lock" is not a standard command, and running npm update --no-save will update the package.json file if used. Deleting and reinstalling the package is not a recommended approach as it can disrupt your project.
Which Node.js package is commonly used to connect to a MySQL database?
- mysql
- database-connector
- node-mysql
- mysql-connector
In Node.js, the commonly used package to connect to a MySQL database is mysql. This package provides a straightforward way to interact with MySQL databases, allowing you to establish connections and perform database operations. The other options are not standard packages for MySQL database connections.
Which of the following is true about the global object in a Node.js module?
- It is available only within the module where it is declared.
- It is a shared object across all modules in a Node.js application.
- It contains all the global variables of the Node.js runtime.
- It can be modified by any module in the application.
The global object in a Node.js module is available only within the module where it is declared. It is not shared across all modules, and each module has its own isolated scope. The other options do not accurately describe the behavior of the Node.js global object.
What is the difference between a static import and a dynamic import in JavaScript?
- Static import is used to load modules at compile time, and it's part of the ES6 module system.
- Dynamic import is used to load modules at runtime, and it returns a promise that resolves to the module.
- Static import is used for loading ES6 modules, while dynamic import is used for CommonJS modules.
- There is no difference between static and dynamic imports in JavaScript.
Static imports are used at compile time and load modules synchronously, while dynamic imports are used at runtime and load modules asynchronously. Dynamic imports return a promise that resolves to the module.
For optimizing complex queries involving multiple JOIN operations, one can use ________ to break them into simpler ones.
- Subqueries
- Indexes
- Caching
- Temporary Tables
For optimizing complex queries involving multiple JOIN operations, one can use "Subqueries" to break them into simpler, more manageable queries. Subqueries allow you to retrieve intermediate results that can be used in the main query.
What is the significance of the order in which middlewares are defined in Express.js?
- The order of middleware does not matter; Express.js automatically arranges them.
- Middlewares are executed in the reverse order of definition.
- Middlewares are executed in the order of definition.
- Middleware order depends on the priority given when defining routes.
In Express.js, middlewares are executed in the order they are defined. The order matters because each middleware can modify the request or response objects and pass them on to the next middleware.
In Express.js, to limit the middleware execution to a particular HTTP method, you should use the ______ method.
- app.use()
- router.use()
- app.method()
- router.method()
To limit the execution of middleware to a specific HTTP method in Express.js, you should use the router.use() method and specify the HTTP method as an argument, such as router.use('GET', middlewareFunction). This ensures that the middleware is only executed for requests with the specified method.
You are tasked with ensuring that a web application works seamlessly and that all components interact as expected. Which testing approach would be most suitable to verify the interactions between different components and services?
- Unit Testing
- Integration Testing
- Functional Testing
- Usability Testing
To verify interactions between different components and services in a web application, Integration Testing is the most suitable approach. Unit Testing focuses on individual units of code, Functional Testing checks if the application meets its specifications, and Usability Testing focuses on user experience. Integration Testing is specifically designed to test the interactions between components.