In a scenario where a function needs to access the this keyword of a containing object, should an arrow function be used?
- Yes, always
- No, never
- It depends
- Only in classes
Arrow functions should not be used in this scenario because they do not bind their own "this" and instead inherit it from the enclosing scope. This can lead to unintended behavior when trying to access the "this" keyword of a containing object.
Using a WeakMap for private data ensures that the data is garbage collected when the object key is no longer ________.
- Referenced
- Immutable
- Mutable
- Valid
When using a WeakMap for private data, the data is tied to the object key, and it will be garbage collected when the object is no longer referenced elsewhere in the code. This helps in managing memory efficiently for private data in JavaScript.
The _________ method is used to execute a function on each item in a Set.
- forEach
- execute
- loop
- iterate
The correct method is forEach. The forEach method in Set allows you to execute a provided function once for each element in the Set, in insertion order. Example: mySet.forEach((value) => console.log(value));.
What is the main purpose of default parameters in ES6 functions?
- Enhancing Function Flexibility
- Enabling Type Annotations
- Facilitating Function Overloading
- Simplifying Function Parameter Handling
Default parameters in ES6 functions provide a way to set default values for function parameters, enhancing flexibility by allowing functions to be called with fewer arguments or without any arguments. This can simplify code and handle different use cases without requiring explicit checks for undefined values.
How do Promises facilitate handling multiple asynchronous AJAX requests concurrently?
- Promises use a single-threaded model, limiting concurrency.
- Promises cannot handle multiple asynchronous requests concurrently.
- Promises allow chaining, enabling sequential handling of requests.
- Promises support Promise.all() for concurrent handling of multiple requests.
Promises facilitate handling multiple asynchronous AJAX requests concurrently through the Promise.all() method. It takes an array of promises and returns a new promise that fulfills with an array of the resolved values when all promises in the iterable argument have been fulfilled.
In a scenario where multiple API calls are made and you need to wait for all of them to complete, which Promise method would be most appropriate?
- Promise.all()
- Promise.race()
- Promise.any()
- Promise.resolve()
When dealing with multiple asynchronous operations that should all complete before proceeding, Promise.all() is the appropriate method. It takes an array of promises and resolves when all of them have resolved. This ensures that you wait for all API calls to complete before moving forward.
What is functional composition in the context of JavaScript?
- Combining multiple functions to produce a new function
- Transforming data types in JavaScript
- Declaring variables within functions
- Utilizing loops in JavaScript
Functional composition involves combining multiple functions to produce a new function. This technique is commonly used to create more complex and reusable functions by chaining together simpler ones. It promotes a modular and clean coding style, enhancing code readability and maintainability. Understanding functional composition is crucial for writing efficient and scalable JavaScript code.
__________ recursion refers to a situation where a recursive function calls itself multiple times within a single step.
- Nested
- Infinite
- Deep
- Tail
In-depth content in the explanation. Recursive functions that call themselves multiple times within a single step are known as deep recursion. This occurs when a function calls itself within a nested structure, leading to multiple recursive calls in one step.
When implementing a recursive function in ES6, what considerations should be made regarding stack overflow?
- Tail call optimization eliminates the risk of stack overflow in all cases.
- It's essential to handle base cases properly to avoid stack overflow.
- Stack overflow is unavoidable in recursive functions in ES6.
- Increasing the stack size is the only solution to prevent overflow.
When implementing recursive functions in ES6, it's crucial to handle base cases effectively to prevent stack overflow. While tail call optimization can help in some cases, it's not universally guaranteed, making proper base case management a fundamental consideration.
A Symbol can be explicitly converted to a string using __________ method.
- toString()
- valueOf()
- convertToString()
- description()
The correct method to explicitly convert a Symbol to a string is toString(). The toString() method is a built-in method for Symbol instances, which returns the string representation of the Symbol.
Which keyword is used to define a class in ES6?
- class
- type
- struct
- interface
In ES6, the class keyword is used to define a class. It provides a cleaner syntax for creating constructor functions and prototypes. Classes allow for easier code organization and inheritance in JavaScript.
What is the primary purpose of destructuring assignment in ES6?
- Simplifying the process of extracting values from arrays or objects
- Declaring variables in a concise manner
- Improving code readability by using shorthand syntax
- Allowing variables to be reassigned easily
Destructuring assignment in ES6 is primarily used to simplify the process of extracting values from arrays or objects, making code more concise and readable. It allows you to declare variables and assign values in a single line, improving code structure.