When used in a function argument, what does the rest operator do with the supplied arguments?
- Gathers them into an array
- Ignores them
- Converts them to a string
- Spreads them to all variables
The rest operator (...) in a function parameter allows you to gather all the remaining arguments into a single array. This is helpful when you have a variable number of arguments and want to process them as an array within the function.
In ES6, how can the spread operator (...) be used in a recursive function?
- Using the spread operator in a recursive function allows for the expansion of an array or iterable, enabling the passing of individual elements as arguments. This can be useful when dealing with variable argument lists in recursive calls.
- The spread operator can be employed to concatenate arrays, ensuring a more efficient handling of recursive calls where arrays need to be merged or combined.
- It is possible to use the spread operator to clone objects within a recursive function, providing a mechanism to duplicate complex data structures without modifying the original objects.
- Utilizing the spread operator in a recursive function helps to flatten nested arrays, simplifying the processing of deeply nested structures in the recursive calls.
The correct usage of the spread operator in a recursive function involves spreading the array or iterable inside the function's argument list. This is particularly helpful when dealing with functions that accept a variable number of arguments, allowing for flexibility in recursive calls.
If a variable declared with const is an object or array, its properties can still be ________.
- Modified
- Deleted
- Reassigned
- Hidden
In JavaScript, when a variable is declared with const, it means the reference to the object or array is constant, not the actual content. Therefore, you can't reassign the variable, but you can still modify, delete, or add properties to the object or array.
Describe a scenario where dynamic imports would be beneficial in a server-side JavaScript environment.
- In an environment where all server-side code is loaded upfront.
- When server-side modules need to be loaded on-demand based on specific requests.
- Only in scenarios where server-side code is minimal.
- Use static imports to include all server-side modules during startup.
Dynamic imports in a server-side JavaScript environment are beneficial when specific modules are required on-demand, such as handling different types of requests. This helps optimize resource usage and improve response times in scenarios with varying workloads.
How do you remove an item from a Map in ES6?
- delete method
- remove method
- pop method
- discard method
In ES6, you can use the delete method to remove an item from a Map. This method takes the key as an argument and removes the corresponding key-value pair from the Map.
How do prototype delegation and proto property in ES6 object literals work?
- They are unrelated concepts in ES6.
- Prototype delegation is achieved through the proto property.
- The proto property is used for inheritance in object literals.
- Prototype delegation is an obsolete feature in ES6.
In ES6 object literals, the proto property is used to establish prototype delegation and achieve inheritance. The proto property allows an object to inherit properties and methods from another object, forming a prototype chain. This mechanism facilitates code reuse and promotes a more modular and extensible design. It is important to note that the proto property is considered an internal implementation detail, and using Object.create() is the recommended approach for explicit prototype delegation.
What is a common challenge or limitation associated with tree shaking in JavaScript applications?
- It may lead to unintentional removal of code with side effects
- Tree shaking is only applicable to server-side code
- It can only eliminate unused variables, not functions
- Tree shaking is only effective in minified code
One challenge with tree shaking is the potential removal of code with side effects. If not handled carefully, it may result in unintended consequences, such as eliminating code that performs actions like setting up event listeners or initializing global variables.
Can methods in ES6 classes be anonymous?
- Yes, by using the anonymous keyword
- No, all methods must have names
- Yes, by omitting the method name
- No, only functions can be anonymous
Yes, methods in ES6 classes can be anonymous by omitting the method name. However, this is not a recommended practice as it makes code less readable. Naming methods helps in understanding the purpose and functionality of the methods within a class.
In what ways can destructuring assignment be utilized in function parameters?
- Extract specific values
- Set default parameter values
- Both 1 and 2
- Neither 1 nor 2
Destructuring assignment in function parameters allows you to extract specific values from objects or arrays passed as arguments. Additionally, you can set default parameter values using destructuring, providing flexibility in handling different cases.
What is the primary advantage of using dynamic imports in JavaScript?
- Code Splitting
- Improved Code Readability
- Faster Execution
- Enhanced Browser Compatibility
Dynamic Imports in JavaScript allow for efficient code splitting. By loading only the modules that are needed at runtime, it improves the performance of the application, especially in large projects where not all code is required on every page.