In ES6, __________ methods allow for concise method definitions without the function keyword.
- Arrow
- Define
- Class
- Prototype
In ES6, arrow functions provide a concise syntax for defining functions. The arrow (=>) is used to declare arrow functions, and they are particularly useful for defining methods on objects without the need for the function keyword. Arrow functions inherit the this value from the enclosing scope, making them convenient for defining methods within ES6 classes.
When a function returns a new object each time it is called, even with the same inputs, is it considered a pure function?
- Yes
- No
- Depends on the type of object
- Only if the object is immutable
A pure function should consistently return the same result for the same inputs, and creating new objects introduces unpredictability, making it impure.
In which scenarios are dynamic imports particularly useful?
- Small Applications
- Large Applications with Code Splitting Needs
- Static Applications
- Mobile Applications Only
Dynamic imports are particularly useful in large applications where code splitting is necessary. This allows loading only the required modules on-demand, reducing the initial load time and improving overall application performance. Small and static applications may not benefit as much from dynamic imports.
How does tree shaking affect the handling of side effects in JavaScript modules?
- Tree shaking removes unused exports during the bundling process, but it may not eliminate side effects.
- Tree shaking automatically handles all side effects, ensuring a clean and efficient codebase.
- Tree shaking has no impact on side effects in JavaScript modules.
- Side effects need to be manually handled regardless of tree shaking.
Tree shaking primarily focuses on eliminating unused exports but doesn't automatically address side effects. Developers must be cautious and handle side effects appropriately in their code.
In the context of Promises and AJAX, how does async/await improve error handling compared to .then() and .catch()?
- It simplifies error handling by using try-catch blocks.
- It requires additional error-checking code.
- It has no impact on error handling.
- It replaces error handling with callbacks.
Async/await improves error handling by allowing the use of try-catch blocks, making code more readable and maintaining a synchronous look and feel. This results in cleaner and more maintainable code, enhancing the developer's ability to handle errors effectively.
When multiple asynchronous tasks are independent of each other, use await with __________ to run them concurrently.
- Promise.all
- Promise.race
- Promise.parallel
- Promise.concurrent
To run multiple independent asynchronous tasks concurrently, use await with Promise.all. This ensures all tasks are completed before proceeding.
Question 1: Consider a project with both Node.js and browser targets. How would you use the ES6 module resolution to handle environment-specific code?
- Use relative paths
- Use absolute paths
- Utilize environment variables
- Utilize conditional imports
In a project targeting both Node.js and browsers, you can use conditional imports to handle environment-specific code. This allows you to import different modules based on the execution environment, improving code maintainability and adaptability. By leveraging the ES6 module system's flexibility, you can create modular and environment-aware code.
How can default parameters in ES6 simplify recursive function calls?
- Default parameters in ES6 allow for the specification of default values when a function is called without providing certain arguments. In recursive functions, this simplifies the base case handling by providing default values when no explicit argument is passed.
- The use of default parameters in recursive functions helps to eliminate the need for explicit base case checks, as the default values act as implicit base cases. This can lead to more concise and readable recursive function implementations.
- ES6 default parameters enable the definition of recursive functions with fewer parameters, reducing the complexity of function signatures and making recursive calls more intuitive.
- Utilizing default parameters in recursive functions facilitates the creation of more generic and adaptable recursive algorithms, allowing for greater flexibility in handling different input scenarios.
Default parameters in ES6 simplify recursive function calls by providing default values, reducing the need for explicit base case handling. This results in cleaner and more concise code, enhancing the readability of recursive functions.
When implementing code splitting using dynamic imports, large bundles are broken into smaller __________.
- Components
- Chunks
- Fragments
- Segments
Code splitting is the technique of breaking large bundles into smaller chunks, and in ES6, this is achieved through dynamic imports, creating separate chunks. Code chunks are often referred to as "chunks" in this context.
Consider a scenario where you have a base class for a UI component and multiple derived classes for specific components. How would the constructors and super keyword play a role in initializing state and props?
- Constructors are unnecessary; use default values for state and props.
- Use constructors for state and props initialization without involving the super keyword.
- Employ both constructors and the super keyword to initialize state and props in a structured manner.
- Rely on setter methods to initialize state and props in UI components.
In a scenario with a base UI component class and derived classes, constructors play a crucial role. Utilizing both constructors and the super keyword ensures a systematic approach to initializing state and props, fostering a clear and organized class hierarchy for UI components.
Can JavaScript handle asynchronous tasks natively, and if so, how is this achieved in relation to the event loop?
- Yes, using callbacks.
- Yes, through asynchronous functions and promises.
- No, JavaScript cannot handle asynchronous tasks natively.
- Yes, through synchronous functions.
JavaScript can handle asynchronous tasks through asynchronous functions and promises. The event loop ensures that asynchronous code is executed at the appropriate time.
To rename a named export during import, use the syntax import { originalName as ______ } from 'module-name';.
- newName
- importedName
- aliasName
- renamedName
When importing a named export and giving it a new name, use the as keyword, making option c) aliasName the correct choice. The syntax is import { originalName as aliasName } from 'module-name';.