Is it possible to create a shared Symbol that is accessible across different parts of your code?
- No, Symbols are always local to the scope they are created
- Yes, Symbols can be shared globally
- Only if Symbols are declared as constants
- Symbols can only be shared within the same function
Symbols can be shared globally by using the Symbol.for() method, which creates a shared Symbol registry accessible across different parts of your code. This promotes consistency and reusability.
In ES6 Modules, imports and exports must be ________, unlike in CommonJS where they can be dynamic.
- Explicit
- Implicit
- Dynamic
- Conditional
In ES6 modules, imports and exports must be explicit, meaning they are statically determined at compile-time. This allows for better tooling support and optimizations. CommonJS, on the other hand, allows dynamic imports and exports.
Arrow functions are not suitable for methods that need their own this context, such as ________ functions.
- Event
- Callback
- Constructor
- Recursive
Arrow functions do not have their own this context, making them unsuitable for methods that need access to the object's this value. Constructor functions, which initialize objects and rely on this, should not be implemented using arrow functions.
How does destructuring work when the structure of the object does not match the destructuring pattern?
- It throws a syntax error
- It assigns undefined to the variables
- It ignores the mismatched values
- It automatically corrects the structure
Destructuring in JavaScript allows extracting values from objects or arrays, and when the structure doesn't match, it simply ignores the mismatched values, assigning undefined to the corresponding variables. This behavior is useful for extracting only the needed values and ignoring the rest.
__________ methods in ES6 classes are methods that are bound to the class itself, not to instances of the class.
- Static
- Instance
- Prototype
- Class
Static methods in ES6 classes are defined using the static keyword and are bound to the class itself rather than to instances of the class. These methods are associated with the class constructor and are called on the class, not on instances. Static methods are often used for utility functions that are related to the class but don't depend on specific instance data.
When building a localization library, how could template literals be used to manage dynamic content?
- They allow for easy integration of variables representing language-specific content.
- They simplify the translation process by providing a concise syntax for language keys.
- They enable the dynamic loading of language-specific templates at runtime.
- They automatically detect the user's language and adjust the content accordingly.
Template literals are valuable in localization by facilitating the integration of variables for dynamic content in different languages.
When importing a named export, what syntax must you use?
- import { exportName } from 'module';
- import * as exportName from 'module';
- import { exportName } as 'alias' from 'module';
- import exportName from 'module';
When importing a named export in ES6, you use the syntax import { exportName } from 'module';. This allows you to bring in a specific exported item from the module.
The Array method __________ is an example of a higher-order function that takes a function as its argument.
- Map
- Filter
- Reduce
- Concat
The reduce method in JavaScript arrays is a higher-order function that takes a callback function to accumulate the elements of an array into a single result. It is commonly used for tasks like summing or product accumulation.
When implementing a module that provides extension hooks, how can Symbols be used to create non-conflicting method names?
- Using generic function names
- Using Symbols as method names
- Using random strings as method names
- Using module-specific prefixes
The correct option is using Symbols as method names. Symbols allow you to create non-conflicting method names by using them as keys for object properties. This is particularly useful in the context of module extension hooks, where different modules can use Symbols without risking naming conflicts. Generic function names, random strings, and module-specific prefixes may lead to conflicts, making Symbols a more suitable choice for this scenario.
Object literals in ES6 can include __________, a shorthand for defining functions.
- Arrow Functions
- Prototypes
- Generators
- Callbacks
ES6 introduced arrow functions as a shorthand for defining functions within object literals, offering a more concise syntax and lexically scoped 'this'.