If you try to import a non-existent named export, it will result in an error at runtime. It's important to ensure that the named exports you are trying to import actually exist in the module.

The yield* keyword in a generator function is used for delegating to another generator or iterable. It allows you to compose generators and is often used for iterating over iterable objects within the generator function. On the other hand, yield is used to pause the generator and yield a value to the caller.

Tagged template literals provide a powerful mechanism for customizing string output, making them beneficial in scenarios where dynamic content manipulation is necessary, such as in i18n (internationalization) or code generation. Regular template literals are simpler and more suitable for static strings.

When handling JSON data in a Fetch API call, it's crucial to use the .json() method to parse the response properly. This method returns a promise that resolves with the result of parsing the body text as JSON, ensuring proper handling of JSON data.

In ES6, custom iterable objects are created by implementing the next method with the iterator protocol. This method should return an object with the value and done properties. This allows the object to be iterated using a for...of loop.

Within a static method, 'this' refers to the class itself, not an instance. This is because static methods are called on the class, not on instances, and they operate on class-level functionality. Therefore, 'this' inside a static method points to the class constructor, allowing access to static properties and methods.

Currying in JavaScript can help in creating functions that are specialized to specific scenarios. Currying is a technique where a function with multiple arguments is transformed into a series of functions, each taking a single argument. This enables creating more specialized functions tailored to specific use cases.

Placing a try/catch block at the beginning of an async function allows you to catch and handle synchronous errors within the asynchronous context. This is important for comprehensive error handling in asynchronous code.

To catch HTTP errors when using the fetch API, you can use the catch method. This method is chained to the Promise returned by fetch and allows you to handle network errors, as well as HTTP errors (e.g., 404 or 500). By providing a callback function to catch, you can manage and respond to errors that may occur during the request.

When an async function throws an unhandled error, it results in a rejected Promise. The rejection carries the error information, and if not caught using a catch block or try...catch, it can lead to unhandled promise rejections. Understanding this behavior is essential for effective error handling in asynchronous code. Properly handling promise rejections ensures that errors are appropriately addressed, preventing unintended consequences in the application.

Composition in ES6 involves creating objects by combining multiple objects that provide functionality. This promotes a modular and reusable code structure by assembling smaller pieces to form more complex objects.

Yes, default parameters in ES6 can be expressions or function calls. This enables dynamic default values based on the evaluation of expressions or the result of function calls. It provides flexibility and allows for more sophisticated default values in function parameters.