Which of the following is an advantage of Redux's architecture when dealing with asynchronous actions?
- Automatic caching of API responses.
- Built-in support for GraphQL queries.
- Predictable and organized state updates through middleware.
- Simplified component lifecycle management.
Redux's architecture offers the advantage of predictable and organized state updates when dealing with asynchronous actions. Redux middleware allows you to intercept and handle asynchronous actions, making it clear how and when state changes occur. This predictability can help avoid race conditions and maintain a consistent application state.
When a component extends ________, it automatically implements shouldComponentUpdate with a shallow comparison of state and props.
- Component
- PureComponent
- React.Component
- React.PureComponent
When a component extends React.PureComponent, it automatically implements shouldComponentUpdate with a shallow comparison of state and props. This shallow comparison helps in optimizing rendering by preventing unnecessary updates when there are no actual changes to state or props.
In a web application, there's a requirement to render tooltips directly under the body tag to ensure they always appear on top, but the tooltip logic is nested deep within other components. How can this be achieved in React?
- React.forwardRef()
- React.lazy()
- React.memo()
- ReactDOM.createPortal()
To render tooltips directly under the body tag and ensure they appear on top, you can use ReactDOM.createPortal(). This function allows you to render a React component at a different DOM location, ensuring it's not affected by the hierarchy of nested components. This is commonly used to create overlays like tooltips and modals.
In React Router, the ________ prop in the Route component allows passing props directly to the rendered component.
- "component"
- "render"
- "children"
- "props"
In React Router, the "render" prop in the Route component allows passing props directly to the rendered component. This is particularly useful when you need to pass additional props or perform logic before rendering the component associated with a specific route. The other options ("component," "children," and "props") are not used for this specific purpose.
In a large application where tracking state changes is becoming complex, which library could help manage state updates using a more concise and readable syntax, while ensuring immutability?
- Immer
- Lodash
- MobX
- Redux-Saga
In a large application with complex state changes, the library that can help manage state updates using a more concise and readable syntax while ensuring immutability is Immer. Immer simplifies state updates by allowing you to write code that appears mutable but actually produces immutable updates. It's particularly useful when dealing with deeply nested state structures.
The useReducer hook is especially useful when the next state depends on the ________ state.
- Current
- Global
- Initial
- Previous
The useReducer hook in React is particularly useful when the next state depends on the global state, often referred to as the previous state. It allows developers to manage state transitions and complex logic more effectively, making it a valuable tool in scenarios where state updates are interdependent.
The process by which a service worker takes control of a page and becomes active is known as ________.
- Activation
- Initialization
- Installation
- Registration
The process by which a service worker takes control of a page and becomes active is known as activation. Service workers go through several lifecycle phases, and activation is the point at which the service worker becomes active and can start intercepting network requests.
Using CSS Modules in React, class names are made locally scoped by default and transformed into a unique ______ during the build process.
- class
- hash
- identifier
- style
In CSS Modules, class names are indeed made locally scoped by default to avoid naming conflicts. These class names are transformed into unique hashes during the build process, ensuring that they won't clash with other styles elsewhere in the application. So, the correct answer to fill in the blank is "hash."
In styled-components, how can you pass props to your styles?
- By defining styles in a separate JavaScript file.
- By passing them as arguments to template literals.
- By using CSS classes.
- You can't pass props to styles.
In styled-components, you can pass props to your styles by passing them as arguments to template literals. This allows you to conditionally apply styles based on the props of a component. It's a powerful feature that enables dynamic styling based on the component's state or data, making your UI more flexible and responsive.
What is a "Render Prop" in the context of React?
- A design pattern for sharing code between components.
- A function prop that a component uses to share its state.
- A method for rendering components only in development mode.
- A way to style React components.
In React, a "Render Prop" is a technique where a component's prop is a function that it uses to share its internal state or some behavior with its child components. This allows for a flexible way to compose components and share logic between them. It is not related to styling or rendering modes.