To handle errors in dynamic imports, use a __________ block.
- try-catch
- catch
- error
- finally
When using dynamic imports, it is recommended to use a try-catch block to handle potential errors that may occur during the loading of the dynamically imported module.
What is the primary role of the call stack in JavaScript execution?
- Manages function calls and keeps track of execution contexts
- Stores global variables
- Executes asynchronous code
- Manages browser events
The call stack in JavaScript is responsible for managing function calls. It keeps track of the execution contexts and the order in which functions are called. Understanding the call stack is crucial for comprehending the flow of execution in JavaScript programs.
How does a tagged template literal differ from a regular template literal?
- A tagged template literal is enclosed in backticks and allows expressions to be embedded.
- A regular template literal is enclosed in single quotes and cannot contain expressions.
- A tagged template literal can be used for multiline strings.
- A regular template literal cannot be assigned to a variable.
In a tagged template literal, a function (the tag function) is invoked, receiving the template string and evaluated expressions as arguments. This allows for custom string processing. Regular template literals do not involve a tag function.
What is the main difference between default and named exports in ES6 modules?
- Default exports allow exporting a single value or function per module, while named exports allow exporting multiple values with distinct names.
- Default exports can only be used with functions, whereas named exports can be used with any type of value.
- Default exports are used for private components, while named exports are used for public components.
- Default exports require an additional keyword for import, unlike named exports.
In ES6 modules, default exports are used to export a single value or function, while named exports allow exporting multiple values with distinct names. Default exports are particularly useful when there is only one main entity to be exported from a module.
Custom iterators can be created in JavaScript by defining a class with a Symbol.iterator method that returns an object implementing the _______ method.
- iterate()
- execute()
- iterator()
- next()
In JavaScript, custom iterators are created by defining a class with a Symbol.iterator method, and the method that needs to be implemented is 'next.' The Symbol.iterator method should return an object with a 'next' method.
How do iterators use the next() method, and what does it return?
- Iterators use next() to move to the next element and return an object with value and done properties
- Iterators use next() to check if an element exists and return a boolean value
- Iterators use next() to retrieve the previous element
- Iterators use next() to skip to the end of the iteration
The next() method is called on an iterator to move to the next element in the iteration. It returns an object with two properties: value, which contains the current element, and done, a boolean indicating whether the end of the iteration has been reached. This allows for controlled and step-by-step iteration over a sequence of values.
When designing a class for a UI component, how would you define a method that shouldn't be accessible outside of the class?
- Private Methods
- Protected Methods
- Public Methods
- Static Methods
In ES6, to create a method that is not accessible outside of the class, you can use the # symbol before the method name, making it a private method. Private methods are encapsulated within the class, ensuring they are not accessible externally. This helps in controlling access to specific functionalities and maintaining the integrity of the class.
When designing a function to log user activity, what considerations should be made to maintain purity and manage side effects?
- Store logs in a global array
- Use asynchronous logging for better performance
- Log only user actions without any additional data
- Separate the logging logic from the main function
To maintain purity and manage side effects, the logging logic should be separated from the main function. This separation helps in isolating the side effect (logging) and makes the main function pure. Storing logs in a global array or mixing logging with the main function can lead to impurity.
In the context of recursion, how can destructuring assignments in ES6 improve code clarity?
- Destructuring assignments have no impact on code clarity in recursive contexts.
- They can introduce confusion in recursive code.
- Destructuring assignments can simplify accessing nested values.
- They only work with arrays and not objects in recursive scenarios.
Destructuring assignments in ES6 can enhance code clarity by simplifying the extraction of values from complex data structures. When dealing with recursive data, they make it easier to access nested values, leading to cleaner and more readable code.
What is a static method in an ES6 class?
- A method that can only be called on instances of the class
- A method that belongs to the class rather than an instance
- A method that is defined using the static keyword
- A method that cannot be accessed outside the class
In ES6, a static method is a method that belongs to the class itself rather than an instance. It is defined using the static keyword and can be called on the class itself, not on instances. This allows you to perform operations that are not specific to any instance but are related to the class as a whole.