In a project where tree shaking is vital for performance, how do you decide between using named and default exports?
- Using named exports for small utility functions and default exports for larger, more central functionalities
- Using default exports for small utility functions and named exports for larger, more central functionalities
- Exclusively using named exports to facilitate tree shaking
- Exclusively using default exports to facilitate tree shaking
When tree shaking is crucial for performance, using named exports for smaller utility functions allows for more granular control over what gets included in the bundle. For larger, more central functionalities, default exports can be beneficial. This approach ensures that only necessary code is bundled, improving the efficiency of tree shaking in eliminating unused code.
Describe the implementation of an async function that awaits user input and then processes it.
- Utilize prompt for user input within the async function
- Implement a callback for user input and await its resolution
- Use await with a promise-based input function
- Incorporate async/await with setTimeout for user input
To implement an async function awaiting user input, you can use await in combination with a promise-based input function. This ensures that the function pauses execution until user input is received, maintaining the asynchronous nature of the application.
In a function that generates HTML content, how would template literals enhance code readability and maintainability?
- They allow embedding variables directly in the string, reducing concatenation complexity.
- They provide a more concise syntax for creating HTML templates.
- They enable the use of complex expressions within the template, improving flexibility.
- They simplify the inclusion of special characters in the HTML content.
Template literals allow for more readable and maintainable code by directly embedding variables and expressions, reducing the need for complex string concatenation.
What is the difference in error handling between then/catch and async/await syntax?
- then/catch is used with synchronous code, and async/await is used with asynchronous code
- then/catch is promise-based, and async/await is generator-based
- then/catch is chaining, and async/await uses try/catch
- then/catch is for handling resolved values, and async/await is for handling rejections
The key difference lies in syntax and structure. then/catch involves chaining promises, while async/await uses a more synchronous and linear try/catch structure. async/await provides a cleaner and more readable way to handle asynchronous operations.
How does error handling differ between traditional callbacks and Promises?
- Callbacks: Handle errors using traditional try-catch blocks.
- Promises: Errors are handled using .catch() method.
- Callbacks: Error handling is scattered, making it harder to manage.
- Promises: Provides a more structured and centralized approach to error handling.
In traditional callbacks, error handling relies on try-catch blocks within each callback, leading to scattered code. Promises offer a cleaner approach with a dedicated .catch() method, providing centralized error handling and making the code more readable and maintainable.
What is the main difference between using XMLHttpRequest and the Fetch API in terms of handling responses?
- Fetch API returns a Promise that resolves with the Response
- XMLHttpRequest directly returns the Response object
- Fetch API uses callbacks for response handling
- XMLHttpRequest handles responses synchronously
The Fetch API returns a Promise that resolves with the Response object, providing a more modern and convenient way to handle responses. XMLHttpRequest, on the other hand, relies on direct access to the Response object without the benefits of Promises.
Can a method in an ES6 class be both static and async?
- Yes
- No
- Depends on the method implementation
- Only if the class is marked as async
Yes, a method in an ES6 class can be both static and asynchronous. Static methods are called on the class itself, not on instances, and async methods use the async keyword to indicate asynchronous behavior. Combining these allows the creation of static methods that perform asynchronous tasks.
What is the syntax difference between method definitions in ES6 classes and traditional function expressions?
- ES6 classes use the function keyword
- ES6 classes use the method keyword
- ES6 classes use the def keyword
- ES6 classes use the => arrow syntax
The syntax difference lies in ES6 classes using the => arrow syntax for method definitions, providing a more concise way compared to traditional function expressions. The arrow function automatically binds the method to the class instance.
To handle errors in dynamic imports, use a __________ block.
- try-catch
- catch
- error
- finally
When using dynamic imports, it is recommended to use a try-catch block to handle potential errors that may occur during the loading of the dynamically imported module.
What is the primary role of the call stack in JavaScript execution?
- Manages function calls and keeps track of execution contexts
- Stores global variables
- Executes asynchronous code
- Manages browser events
The call stack in JavaScript is responsible for managing function calls. It keeps track of the execution contexts and the order in which functions are called. Understanding the call stack is crucial for comprehending the flow of execution in JavaScript programs.