In a scenario where multiple API calls are made and you need to wait for all of them to complete, which Promise method would be most appropriate?
- Promise.all()
- Promise.race()
- Promise.any()
- Promise.resolve()
When dealing with multiple asynchronous operations that should all complete before proceeding, Promise.all() is the appropriate method. It takes an array of promises and resolves when all of them have resolved. This ensures that you wait for all API calls to complete before moving forward.
How do Promises facilitate handling multiple asynchronous AJAX requests concurrently?
- Promises use a single-threaded model, limiting concurrency.
- Promises cannot handle multiple asynchronous requests concurrently.
- Promises allow chaining, enabling sequential handling of requests.
- Promises support Promise.all() for concurrent handling of multiple requests.
Promises facilitate handling multiple asynchronous AJAX requests concurrently through the Promise.all() method. It takes an array of promises and returns a new promise that fulfills with an array of the resolved values when all promises in the iterable argument have been fulfilled.
In ES6, how does the spread operator enhance the functionality of higher-order functions?
- Allows the spreading of elements in an array or properties in an object
- Facilitates the creation of closures within higher-order functions
- Enables the use of async/await syntax in functions
- Enhances the performance of recursion in functional programming
The spread operator in ES6 allows the spreading of elements in an array or properties in an object, making it useful for operations like array concatenation and object merging within higher-order functions.
What is the primary purpose of destructuring assignment in ES6?
- Simplifying the process of extracting values from arrays or objects
- Declaring variables in a concise manner
- Improving code readability by using shorthand syntax
- Allowing variables to be reassigned easily
Destructuring assignment in ES6 is primarily used to simplify the process of extracting values from arrays or objects, making code more concise and readable. It allows you to declare variables and assign values in a single line, improving code structure.
How does currying affect the number of arguments a function receives?
- Increases the number of arguments
- Decreases the number of arguments
- Does not affect the number of arguments
- Allows variable number of arguments
Currying in JavaScript involves breaking down a function with multiple arguments into a series of functions, each taking a single argument. This decreases the number of arguments a function receives, making it more flexible and easier to compose with other functions.
To handle multiple asynchronous tasks with Promises, the Promise._______ method is used, which runs multiple promises in parallel.
- race
- all
- resolveAll
- parallel
The correct option is 'all.' The Promise.all method is used to handle multiple asynchronous tasks with Promises by running multiple promises in parallel. It waits for all promises to resolve and returns an array of their results. The 'race' method resolves or rejects as soon as one of the promises in an iterable resolves or rejects.
Default parameters in a function are used when no argument or ________ is passed.
- undefined
- nan
- nan
- value
Default parameters in a function are used when no argument or undefined is passed. In JavaScript, if a parameter is not passed or is explicitly passed as undefined, the default value assigned to that parameter is used.
What is the key difference in loading dependencies in ES6 Modules compared to CommonJS?
- Imports are hoisted in ES6 Modules
- Synchronous loading in ES6 Modules
- Asynchronous loading in ES6 Modules
- No loading differences
In ES6 Modules, dependencies are loaded asynchronously, allowing for better performance and parallelism. This is in contrast to CommonJS, which loads modules synchronously.
How does the for...of loop interact with iterables in JavaScript?
- The for...of loop automatically iterates over the values of an iterable, making it easier to work with collections like arrays and strings.
- The for...of loop is used only with arrays and not with other iterables.
- The for...of loop is an obsolete feature in JavaScript.
- The for...of loop requires an explicit iterator method.
The for...of loop simplifies the process of iterating over iterables, providing a cleaner syntax compared to traditional for loops. It automatically calls the iterator's next() method and iterates until the done property becomes true.
What is the main purpose of an iterable in JavaScript ES6?
- Iterables allow you to represent a sequence of values that can be iterated (looped) over.
- Iterables are used for defining constants in JavaScript.
- Iterables help in creating asynchronous functions.
- Iterables provide a way to declare variables in JavaScript.
In JavaScript ES6, iterables are objects that implement the iterable protocol, allowing them to be looped over using the new for...of loop. They are crucial for working with collections of data, enabling efficient and concise iteration.