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.
What is the primary difference between null and undefined in JavaScript?
- null represents an intentional absence of any value, while undefined indicates a variable has been declared but has not been assigned a value.
- null represents a numeric value of zero, while undefined represents an empty string.
- null is used for variables that are out of scope, while undefined is used for variables with no value.
- null is a boolean value, while undefined is a number.
In JavaScript, null represents the intentional absence of any value, while undefined indicates that a variable has been declared but has not been assigned a value. Understanding this difference is crucial for handling data in JavaScript effectively.
Which method of the response object is used to end the response process in an HTTP server?
- response.end()
- response.finish()
- response.complete()
- response.stop()
The response.end() method is used to end the response process in an HTTP server. It finalizes the response and sends it to the client. The other options are not valid methods for ending the response.
How do you include partial views in EJS templates?
- <%- include('partial') %>
- <% include('partial') %>
- <% partial('partial') %>
- <%- partial('partial') %>
In EJS, you can include partial views using the <%- include('partial') %> syntax. This allows you to reuse and insert content from other EJS files into your main template, helping you create modular and maintainable views. The other options are not the correct syntax for including partials in EJS.
The ______ command can be used to update the package.json file to match the actual versions installed in the node_modules directory.
- npm install
- npm update
- npm sync
- npm check
The npm update command can be used to update the package.json file to match the actual versions installed in the node_modules directory. This command will update the version numbers of packages in package.json based on the versions currently installed.
To optimize CRUD operations in a high-write-load scenario, employing ______ strategies like write-behind caching can be effective.
- Caching
- Synchronization
- Scaling
- Indexing
To optimize CRUD operations, caching strategies like write-behind caching can be effective, where data is cached and written back to the database asynchronously. Caching reduces the need to access the database for every write operation, improving performance.