Can default parameters be expressions or function calls?
- No, only primitive values are allowed
- Yes, any valid expression or function call is allowed
- Only function calls are allowed
- Only arrow function expressions are allowed
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.
Composition in ES6 involves creating objects by combining multiple __________ that provide functionality.
- Promises
- Objects
- Prototypes
- Modules
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.
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.
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.
Imagine you are creating a gaming application with different types of characters. How would you use inheritance in ES6 classes to implement shared behaviors?
- Object Composition
- Using Mixins
- Extending Base Class
- Function Constructors
In this scenario, you would extend a base class to create subclasses for each character type. Option A is about combining objects, Option B is about sharing functionality through mixins, and Option D is an older approach not commonly used in ES6.