Node.js uses the .mjs file extension for ES6 modules to differentiate them from CommonJS modules that typically use the .js extension. This helps Node.js to identify the module type and apply the appropriate module loading mechanism.

Yes, a static method in a parent class can be overridden in a child class. However, it's important to note that static methods are associated with the class itself rather than instances, and the child class can provide its own implementation of the static method, effectively overriding the one in the parent class.

The spread operator can be used to clone an array without mutating the original array. It creates a shallow copy, meaning nested objects are still references, but the outer array is a new instance.

In JavaScript, default parameters are evaluated at the time of the function call. Explanation should cover the order of declaration and how the referencing works.

In a static method, super refers to the parent class's static context. This is useful for accessing static methods or properties of the parent class.

To execute multiple asynchronous functions concurrently and wait for all of them to complete, the appropriate method is Promise.all(). It takes an array of promises and resolves when all the promises in the array have resolved. Promise.race() would resolve as soon as any of the promises in the array resolves, which might not be suitable for waiting for all of them. Understanding the correct usage of Promise.all() is crucial for efficient handling of parallel asynchronous tasks.

ES6 Modules have a static structure, allowing tools to analyze dependencies at build time. Tree shaking is the process of eliminating dead code, and ES6 Modules excel in this regard, making it easier to eliminate unused code during bundling.

In ES6, the shorthand for method properties allows omitting the 'function' keyword when defining methods in object literals. It enhances code readability by providing a more concise syntax for method definitions within objects. This syntactic sugar simplifies the declaration of methods in objects, making the code cleaner and more modern.

The concept of referential transparency is essential in understanding how functions are combined in functional composition. Referential transparency means that a function, given the same inputs, will always return the same output, allowing for easier reasoning about the behavior of composed functions.

ES6 object literals allow the use of computed property names, which is particularly beneficial in scenarios where dynamic property names are based on user input. Computed property names enable the creation of object properties dynamically based on expressions, providing flexibility and conciseness in handling user input.