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 of the following stream types is used for reading data in Node.js?
- Writable Stream
- Readable Stream
- Duplex Stream
- Transform Stream
Readable Streams are used for reading data in Node.js. They allow you to read data from various sources, such as files, HTTP requests, and more, in a non-blocking and efficient manner.
A ______ cache stores data in a shared location that can be accessed by multiple application instances.
- Shared
- Distributed
- Local
- In-Memory
A Distributed cache stores data in a shared location that can be accessed by multiple application instances. This allows multiple nodes of an application to share cached data, improving performance and reducing redundancy.
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.
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.
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.
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.