In a scenario where you need to create a custom data structure (like a tree), how would you make it iterable?
- Implement the iterable protocol by defining a Symbol.iterator method
- Use the Array.from() method to convert the data structure to an array
- Utilize the for...in loop to iterate over the data structure
- Create a custom iterate method for the data structure
Making a custom data structure iterable involves implementing the iterable protocol by defining a Symbol.iterator method. This method should return an iterator object with a next method, allowing the data structure to be iterated using the for...of loop or other iterable mechanisms in JavaScript.
How does error propagation work in a Promise chain?
- Propagates to the nearest catch block
- Propagates to the outermost catch block
- Propagates to the nearest then block
- Propagates to the global error handler
In a Promise chain, errors propagate to the nearest catch block. If there isn't a catch block in the immediate chain, it continues to propagate outward until it finds one. This behavior allows for more granular error handling based on where the error occurs in the chain.
For side effects only, import a module without any exported bindings using import '________';.
- module-name'
- {} from 'module-name'
- from 'module-name'
- module-name';
When importing a module for its side effects only, you can use import 'module-name'; without any specific binding. This is useful when a module has side effects like modifying the global scope.
ES6 allows the use of ________ to dynamically create property names in object literals.
- Template Literals
- Default Parameters
- Rest Parameters
- Spread Operator
Template literals in ES6 provide a powerful way to create strings, allowing dynamic expression evaluation. This feature is often used to create dynamic property names in object literals.
In ES6, can the rest operator be used in conjunction with destructuring to extract specific elements from an array?
- Yes, the rest operator allows extracting specific elements by using the spread syntax.
- No, the rest operator can only be used to extract all elements in an array.
- Yes, the rest operator can be combined with destructuring to extract specific elements.
- No, the rest operator is not compatible with array destructuring.
In ES6, the rest operator can indeed be used in conjunction with array destructuring to extract specific elements. It allows you to capture the remaining elements of an array into a new array variable.
When using default export, you can rename the imported module without using the _________ syntax.
- import customName from
- import as customName from
- import {customName} from
- import default as customName
In ES6, when importing a module with a default export and renaming it, you use the import customName from 'moduleName'; syntax. The as keyword is not required in this context.
What method is used to resume the execution of a generator function?
- resume()
- continue()
- next()
- run()
The correct method to resume the execution of a generator function is next(). This method is called on the Generator object and proceeds to the next yield statement, returning the yielded value. Options a), b), and d) are incorrect and not used for resuming a generator function.
Tagged template literals allow you to parse template literals with a _________ function.
- Regular
- Parse
- Tag
- Transform
In ES6, tagged template literals use a tag function to parse the template literal. This function, often referred to as the tag, allows you to process the template and its interpolated values before producing the final string.
How does the 'use strict' mode affect class behavior in ES6?
- It enforces stricter type checking in class properties
- It allows for dynamic addition of properties in a class
- It has no impact on class behavior
- It throws an error if the class contains undeclared variables
In 'use strict' mode, the class behavior becomes more rigid. It disallows the usage of undeclared variables, ensures that the 'this' keyword behaves more predictably, and generally promotes safer coding practices.
If a property is not found on an object, JavaScript looks up the property on the object's prototype, known as the _________ chain.
- Prototype
- Scope
- Inheritance
- Execution
In JavaScript, the process of searching for a property involves traversing the prototype chain. If the property is not found on the object, it looks up in the prototype chain until it finds the property.