In Node.js, ES6 Modules have a different file extension (_________) compared to CommonJS modules (.js).

  • .mjs
  • .es6
  • .es
  • .node
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.

Can a static method in a parent class be overridden in a child class?

  • Yes
  • No
  • Depends on the method implementation
  • Only if explicitly declared as override
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 in ES6 to clone an array without ________ the original array.

  • Modifying
  • Changing
  • Altering
  • Mutating
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.

If a default parameter references another parameter, what order must they be declared in?

  • After the parameter it references
  • Before the parameter it references
  • It doesn't matter
  • They must be declared in a separate function
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.

The super keyword in static methods refers to the _______ class's static methods and properties.

  • Parent
  • Child
  • Sibling
  • Derived
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 async functions in parallel and wait for all of them, use __________.

  • Promise.all()
  • Promise.race()
  • Promise.parallel()
  • Promise.sequence()
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.

How does the static structure of ES6 Modules aid in tree shaking compared to CommonJS?

  • Easier debugging due to explicit dependencies
  • Improved dead code elimination
  • Faster runtime performance
  • Better support for dynamic imports
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, how does the shorthand for method properties affect the 'function' keyword in object literals?

  • It removes the need for the 'function' keyword.
  • It enforces the use of the 'function' keyword.
  • It modifies the behavior of the 'function' keyword.
  • It's not related to the 'function' keyword.
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 ________ is essential in understanding how functions are combined in functional composition.

  • Closure
  • Immutability
  • Prototypes
  • Referential transparency
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.

In a scenario where dynamic property names are based on user input, how would ES6 object literals be utilized?

  • Utilize computed property names to dynamically assign properties
  • Utilize the Object.assign method for dynamic property assignment
  • Use Object.create for dynamic property generation
  • Implement a switch statement for dynamic property naming
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.