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.
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.
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.
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.
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.
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.