Destructuring an object within a _________ allows for directly mapping object properties to function parameters.
- Callback function
- Template literal
- Arrow function
- Promise
Destructuring an object within an "Arrow function" allows for directly mapping object properties to function parameters. Arrow functions provide a concise syntax, and when combined with destructuring, you can streamline the mapping of object properties to function parameters.
To check if a Map contains a certain key, use the _________ method.
- hasKey
- checkKey
- has
- includes
The correct method is has. In JavaScript, the Map object has a has method that returns a boolean indicating whether the map contains a specified key. Example: myMap.has('key').
How does chaining array methods like map and filter affect performance?
- Negatively impacts performance due to multiple iterations
- Positively impacts performance by optimizing the code
- No significant impact on performance
- Only affects readability, not performance
Chaining array methods like map and filter can negatively impact performance due to multiple iterations. Each method creates a new array, and chaining them leads to intermediate arrays, causing additional iterations. This can be inefficient, especially for large datasets.
In advanced functional composition, ________ functions can be used to enhance readability.
- Pure
- Higher-order
- Impure
- Recursive
In advanced functional composition, higher-order functions can be used to enhance readability. Higher-order functions are functions that can take other functions as arguments or return them as results, providing a powerful tool for composing complex behavior while maintaining code clarity.
What is the role of the catch block in an async/await function?
- It is not required in async/await functions.
- It catches errors that occur within the asynchronous operations.
- It is used to handle successful outcomes in asynchronous operations.
- It is used to handle errors that occur during the execution of the async function.
The catch block in an async/await function is crucial for handling errors that might occur during the execution of asynchronous operations. It allows developers to gracefully handle and manage errors in asynchronous code, ensuring a more robust and reliable application.
In a class, static properties can be accessed using the class name followed by _________.
- Parentheses
- Square Brackets
- Curly Braces
- Dot Notation
To access static properties in a class, you use the class name followed by dot notation. This distinguishes them from instance properties and makes it clear that you are working with a property associated with the class itself, not an instance.
How does the event loop contribute to the non-blocking behavior in a Node.js server handling multiple I/O operations?
- The event loop allows Node.js to delegate I/O operations to background threads or external processes, preventing them from blocking the main thread. The event loop ensures that once I/O operations complete, their callbacks are queued for execution, maintaining non-blocking behavior.
- The event loop in Node.js efficiently manages I/O operations by offloading them to background threads or external processes. This prevents the main thread from being blocked, and the event loop ensures that once I/O operations complete, their callbacks are prioritized for execution.
- Node.js utilizes the event loop to offload I/O operations, preventing them from blocking the main thread. The event loop ensures that once I/O operations are finished, their callbacks are queued for execution, contributing to the non-blocking nature of Node.js servers.
- The event loop in Node.js handles I/O operations asynchronously, preventing them from blocking the main threaOnce I/O operations are complete, their callbacks are queued and prioritized for execution, maintaining non-blocking behavior.
The event loop plays a crucial role in ensuring the non-blocking behavior of Node.js servers handling multiple I/O operations. It offloads I/O operations to background threads or external processes, preventing the main thread from being blocked. The event loop then manages the completion of I/O operations by queuing their callbacks for execution, contributing to the overall efficiency of handling concurrent I/O tasks.
In a WeakSet, the existence of an object in the set does not prevent it from being ________ by the garbage collector.
- Referenced
- Mutated
- Duplicate
- Garbage collected
The objects in a WeakSet are weakly held, similar to WeakMap, allowing them to be garbage collected even if they are present in the WeakSet. This is useful for managing sets of objects when their presence should not hinder garbage collection.
How do higher-order functions contribute to a functional programming style in JavaScript?
- Enable the creation of more concise and expressive code by treating functions as first-class citizens
- Allow functions to be passed as arguments and returned as values, facilitating the use of function composition
- Provide a way to encapsulate and abstract behavior, promoting modularity and reusability
- Enable the creation of custom control structures like map, filter, and reduce
Higher-order functions in JavaScript contribute to a functional programming style by allowing functions to be passed as arguments and returned as values, enabling function composition and facilitating modularity and reusability.
A static method can be called without an instance of the class but not without __________ the class.
- defining
- declaring
- instantiating
- referencing
While a static method can be called without creating an instance of the class, it cannot be called without referencing the class itself. This emphasizes the association of the method with the class rather than instances.