To handle multiple AJAX requests concurrently and wait for all to complete, use Promise._______.
- all
- race
- any
- chain
To handle multiple AJAX requests concurrently and wait for all to complete, use Promise.all(). This method takes an array of promises and waits until all of them are resolved or any one is rejected.
In ES6, __________ methods are not enumerable in a class definition.
- static
- prototype
- constructor
- get
In ES6, static methods are not enumerable in a class definition. Static methods are attached to the class itself rather than its instances, and they are not iterated over when enumerating the properties of a class. This distinction is important when dealing with class-related operations.
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.
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 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.
Which module system supports dynamic loading of modules: ES6 Modules or CommonJS?
- ES6 Modules
- CommonJS
- Both support dynamic loading
- Neither supports dynamic loading
ES6 Modules support dynamic loading, allowing modules to be loaded on demand. CommonJS does not provide built-in support for dynamic loading.
Node.js uses the __________ algorithm for resolving module paths in ES6.
- "CommonJS"
- "ECMAScript"
- "ES6"
- "Import"
Node.js uses the "ECMAScript" algorithm for resolving module paths in ES6, adhering to the ECMAScript Module specifications. This enables the use of import statements for module loading.
How does error handling in Promises compare to that in traditional callback patterns?
- Promises provide a centralized .catch() method for error handling, making it more structured.
- Callbacks often rely on try-catch blocks for error handling.
- Error handling is similar in both, with no significant difference.
- Promises don't support error handling.
Promises offer a cleaner and more centralized way of handling errors through the .catch() method. Callbacks, on the other hand, often involve nested try-catch blocks, leading to less readable and more error-prone code. Understanding this difference is crucial for developers transitioning from traditional callback patterns to Promises.
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.
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 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.
Currying transforms a function with multiple arguments into a sequence of functions each taking a single ________.
- Argument, Value, Parameter, Variable
- Value, Parameter, Argument, Input
- Parameter, Input, Variable, Argument
- Input, Value, Argument, Parameter
Currying involves breaking down a function with multiple arguments into a series of functions, each taking a single parameter. This can enhance the flexibility and composability of functions.