Q1: In a project where you are required to create multiple types of user profiles, how would you use prototypes to ensure code reusability and efficiency?
- Utilize Object.create()
- Use Object.assign()
- Employ class inheritance
- Implement mixin patterns
Prototypes play a crucial role in JavaScript's object-oriented design. Utilizing mixin patterns allows you to compose functionalities from multiple objects, ensuring modular and reusable code. This approach helps in creating diverse user profiles by combining specific traits through prototypes.
What happens to the entries in a WeakMap when there are no other references to the key?
- They are automatically removed from the WeakMap
- They are retained in the WeakMap
- They trigger an error
- They are marked for deferred removal
In a WeakMap, entries are automatically removed when there are no other references to the key. This behavior makes WeakMap suitable for scenarios where memory management is crucial, and entries should be tied to the existence of their key elsewhere in the program.
Recursive functions can be used effectively for tasks such as __________ traversal in data structures.
- Depth-first
- Breadth-first
- Pre-order
- Post-order
Recursive functions are commonly employed for depth-first traversal, where the function explores as far as possible along each branch before backtracking.
In a large-scale application with multiple JavaScript modules, how would you apply tree shaking to reduce the size of the deployed bundle?
- Use a bundler like Webpack that supports tree shaking.
- Manually remove unused code from each module.
- Convert the modules to CommonJS format.
- Utilize a code minification tool.
Tree shaking involves removing dead code during the bundling process. Webpack, a popular bundler, has built-in support for tree shaking, making it an efficient choice. Manually removing code or changing the module format is not the standard approach for tree shaking. Code minification is related but doesn't specifically address dead code elimination.
Consider a scenario where you have an iterable data structure with complex logic for each iteration. How would using a for...of loop simplify or complicate the implementation?
- It would simplify the implementation.
- It would complicate the implementation.
- It would have no impact on the implementation.
- It depends on the specific logic involved.
The correct option is "It would simplify the implementation." The for...of loop is designed to iterate over iterable objects, and its syntax is concise and clear. When dealing with complex logic for each iteration, using for...of can enhance code readability and maintainability by focusing on the logic rather than the mechanics of iteration.
In a web application with heavy DOM manipulations and API calls, how would the event loop and call stack manage these operations?
- The event loop ensures that asynchronous operations, like API calls, are offloaded to the browser's APIs and queued in the task queue. The call stack, which handles synchronous operations, prioritizes execution of tasks in the stack.
- The call stack manages synchronous operations, and the event loop coordinates the execution of asynchronous operations, ensuring they don't block the main thread.
- The call stack processes synchronous tasks, and the event loop continuously checks the call stack and task queue, prioritizing tasks based on their readiness for execution.
- The event loop delegates asynchronous tasks to the browser's APIs, which are executed separately from the main threaThe call stack manages synchronous tasks, preventing them from blocking the execution flow.
In a web application, the event loop and call stack work in tandem. The event loop coordinates asynchronous operations, preventing them from blocking the main thread. The call stack manages synchronous tasks, and the event loop offloads asynchronous tasks to the browser's APIs. Understanding this interaction is crucial for optimizing performance in applications with heavy DOM manipulations and API calls.
For side effects only, import a module without any exported bindings using import '________';.
- module-name'
- {} from 'module-name'
- from 'module-name'
- module-name';
When importing a module for its side effects only, you can use import 'module-name'; without any specific binding. This is useful when a module has side effects like modifying the global scope.
ES6 allows the use of ________ to dynamically create property names in object literals.
- Template Literals
- Default Parameters
- Rest Parameters
- Spread Operator
Template literals in ES6 provide a powerful way to create strings, allowing dynamic expression evaluation. This feature is often used to create dynamic property names in object literals.
In ES6, can the rest operator be used in conjunction with destructuring to extract specific elements from an array?
- Yes, the rest operator allows extracting specific elements by using the spread syntax.
- No, the rest operator can only be used to extract all elements in an array.
- Yes, the rest operator can be combined with destructuring to extract specific elements.
- No, the rest operator is not compatible with array destructuring.
In ES6, the rest operator can indeed be used in conjunction with array destructuring to extract specific elements. It allows you to capture the remaining elements of an array into a new array variable.
When using default export, you can rename the imported module without using the _________ syntax.
- import customName from
- import as customName from
- import {customName} from
- import default as customName
In ES6, when importing a module with a default export and renaming it, you use the import customName from 'moduleName'; syntax. The as keyword is not required in this context.