How can you extract route parameters in Express.js from a route URL like "/users/:userId"?

Using req.params.userId
Using req.query.userId
Using req.body.userId
Using req.param.userId

In Express.js, you can extract route parameters using req.params.userId. Route parameters are specified in the URL path with a colon prefix, and you can access them using req.params. The other options are not the correct way to access route parameters.

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To override ESLint rules for specific files or directories, you can create a .eslintignore or ______ file with the patterns of the files or directories to be excluded.

.eslintrc.js
.eslintignore
.eslintconfig
.eslintexclude

To override ESLint rules for specific files or directories, you can create a .eslintignore file with patterns of the files or directories to be excluded from ESLint linting. The other options are not used for this purpose.

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Which of the following events is emitted when data is available to read from a readable stream?

data
readable
onData
available

In Node.js, the 'data' event is emitted when data is available to read from a readable stream. This event allows you to consume the data as it becomes available. The other options are not standard events for this purpose.

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While working on a project, you are required to extract specific properties from objects and assign them to variables. How would you utilize destructuring assignment to efficiently accomplish this task, and what would you do to handle non-existent properties?

const { prop1, prop2 } = sourceObject;
const [prop1, prop2] = sourceObject;
const { prop1, prop2 } = [sourceObject];
const [prop1, prop2] = { ...sourceObject };

To efficiently extract specific properties from objects using destructuring assignment in JavaScript, you would use the syntax const { prop1, prop2 } = sourceObject;. This assigns the values of prop1 and prop2 from sourceObject to the corresponding variables. To handle non-existent properties, you can provide default values like const { prop1 = defaultValue1, prop2 = defaultValue2 } = sourceObject;. The other options are not correct ways to achieve this task.

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In a sharded database architecture, how are Update operations handled across multiple shards?

Updates are broadcast to all shards
A central coordinator handles all updates
Each shard independently handles updates for its data
Updates are queued and processed sequentially

In a sharded database architecture, a central coordinator (Option 2) often handles updates that affect multiple shards. Each shard (Option 3) independently handles updates for its own data, but coordinated updates across shards typically require a central component. Options 1 and 4 are not common methods for handling updates in sharded databases.

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Which command is used to publish a package to the NPM registry?

npm upload
npm publish
npm send
npm push

To publish a package to the NPM registry, you should use the npm publish command. This command packages and uploads your module to the NPM registry, making it available for others to use and install. Options 1, 3, and 4 are not valid commands for publishing packages and might lead to errors.

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How can optimizing database queries significantly reduce the response time of an application?

Optimizing queries can make the code more readable but doesn't affect response time.
Optimizing queries can reduce the number of database calls and minimize data retrieval, improving response time.
Optimizing queries doesn't impact response time; it only reduces server memory usage.
Optimizing queries can speed up server initialization but has no effect on response time.

Optimizing database queries can significantly reduce response time by minimizing the number of database calls, reducing data retrieval, and improving the efficiency of data fetching, ultimately leading to faster responses. The other options either misrepresent the impact of query optimization or provide irrelevant information.

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When performing file operations using the fs module, handling ______ errors is crucial to ensure data integrity.

synchronous
asynchronous
promise
event

When working with file operations in Node.js using the fs module, handling asynchronous errors is crucial. Asynchronous file operations can fail due to various reasons such as file not found, permission issues, or disk full errors. Proper error handling ensures data integrity and prevents unexpected crashes in your application.

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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.

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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.

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