In a scenario with a mix of synchronous and asynchronous code, how does the call stack and event loop manage the execution?
- The call stack executes synchronous code first.
- The event loop processes asynchronous code first.
- Both synchronous and asynchronous code are executed randomly.
- The call stack and event loop have no interaction.
The call stack prioritizes synchronous code, while the event loop manages the execution of asynchronous code by pushing it to the callback queue and executing it when the call stack is empty.
Can mixins in ES6 access private data of the classes they are mixed into?
- Yes, mixins have access to private data
- No, mixins cannot access private data
- It depends on the implementation of the mixin
- Private data is accessible only during class instantiation
Mixins in ES6 do not have direct access to the private data of the classes they are mixed into. Private data remains encapsulated within the class, ensuring data integrity and security.
How would you use a for...of loop to iterate over a string?
- for (let char in myString)
- for (let char of myString)
- for (let i = 0; i < myString.length; i++)
- for (let i = myString.length - 1; i >= 0; i--)
The correct syntax to iterate over a string using a for...of loop is for (let char of myString). This loop simplifies the process of iterating over the characters of a string without the need for an index.
In ES6, a module imported via a relative path starting with ______ indicates it is located in the same directory.
- ./
- ../
- //
- \
When using a relative path in ES6 for module imports, ./ is used to indicate that the module is in the same directory as the importing module.
A class expression in ES6 can be named or unnamed, with the name being accessible inside the class's ________.
- Private Scope
- Protected Scope
- Public Scope
- Local Scope
The name of a class in ES6 is accessible only within the class's block scope, making it part of the class's internal structure.
The _________ dead zone refers to the time during which a let or const variable cannot be accessed.
- temporal
- execution
- initial
- declaration
The correct option is 'initial'. The temporal dead zone occurs between the entering of the scope and the actual declaration of the variable. During this time, trying to access the variable will result in a ReferenceError. It is called the 'initial' dead zone because it happens before the variable is initialized.
What is the main advantage of using Promises over Callbacks in asynchronous JavaScript?
- Synchronous Execution
- Conciseness and Readability
- Callback hell elimination
- Procedural Approach
Promises in JavaScript provide a cleaner and more readable way to handle asynchronous code. With promises, you can avoid nested callbacks, making the code more maintainable. Option B is correct as it highlights the conciseness and readability advantages of using Promises over Callbacks.
How does method definition in ES6 classes affect the prototype chain?
- Adds methods to the subclass only
- Adds methods to the superclass only
- Does not affect the prototype chain
- Adds methods to both the subclass and superclass
In ES6 classes, method definitions impact the prototype chain. When a method is defined in a class, it gets added to the prototype of the class. When a subclass extends a superclass, its prototype chain includes both its own methods and those of the superclass. This ensures proper inheritance and method access.
To convert a Set into an array, use the spread operator like this: [..._________].
- Set
- Map
- Iterable
- Collection
To convert a Set into an array, use the spread operator like this: [...Set]. Sets in ES6 are iterable, and using the spread operator allows you to convert the Set into an array easily.
Using _________ functions helps in maintaining function purity by not altering the original data structure.
- Map
- Reduce
- Pure
- Impure
Using pure functions helps in maintaining function purity by not altering the original data structure. Pure functions always produce the same output for the same input and do not modify external state, contributing to the predictability and reliability of the code.