A colleague is having trouble rendering a dynamic value in their JSX code. They've tried using quotes, but the value renders as a string. What advice would you give?

  • Advise them to use quotes but ensure the value is parsed as a number or boolean if needed.
  • Encourage them to use double curly braces {{}} around the value.
  • Recommend using backticks (`) to enclose the value.
  • Suggest wrapping the value with single curly braces {}.
To render a dynamic value in JSX as the intended value (rather than as a string), it's essential to wrap the value in single curly braces {}. Double curly braces {{}} are used for expressions or variable interpolation within JSX. Backticks (`) are used for template literals and are not appropriate for this case. Using quotes alone will indeed render the value as a string, so the correct approach is to use single curly braces.

In GraphQL, when you want to get real-time data updates, you would use a ________ instead of a regular query.

  • Live Query
  • Reactive Query
  • Real-time Query
  • Subscription Query
In GraphQL, when you want to receive real-time data updates, you would use a "Subscription Query" instead of a regular query. Subscriptions allow you to subscribe to specific events or data changes and receive updates when those events occur. Regular queries are used for retrieving static data, whereas subscriptions are designed for handling real-time data streams.

Your application has users worldwide, and you need to provide social media logins, SSO, and multi-factor authentication. Which service would cater to all these needs?

  • Auth0
  • PayPal Identity
  • Slack Identity
  • TikTok Identity
Auth0 is a popular identity and access management platform that offers a comprehensive solution for authentication needs, including social media logins, single sign-on (SSO), and multi-factor authentication (MFA). It is widely used for providing secure and convenient identity services in applications with global user bases. The other options do not offer such comprehensive identity management.

How can you stop an event from propagating to parent elements in React?

  • By calling e.preventDefault() within the event handler.
  • By using the stopPropagation() method on the event object: e.stopPropagation();
  • By setting e.cancelBubble = true; in the event handler.
  • It's not possible to stop event propagation in React.
To stop an event from propagating to parent elements in React, you should use the stopPropagation() method on the event object, as described in option 2. This method prevents the event from continuing to bubble up the component tree. Option 1 is incorrect, as e.preventDefault() is used to prevent the default behavior of an event, not its propagation. Option 3 is not the recommended way in React, and option 4 is not accurate, as event propagation can indeed be stopped in React.

How does React Transition Group assist in animations within React applications?

  • It manages the state of animations and their lifecycles.
  • It optimizes animations for performance.
  • It provides pre-built animations for common use cases.
  • It simplifies the creation of complex CSS animations.
React Transition Group is primarily responsible for managing the state of animations and their lifecycles. It helps in orchestrating animations smoothly by handling entering and exiting states, making it easier to create complex animations within React applications. While it can be used in combination with CSS for animations, its primary role is managing the animation states.

Which of the following is a benefit of using third-party UI libraries like Material-UI or Ant Design in React applications?

  • Consistency in design and user experience.
  • Increased application size and complexity.
  • Limited flexibility in design.
  • Slower development due to customization.
One of the primary benefits of using third-party UI libraries like Material-UI or Ant Design in React applications is achieving consistency in design and user experience. These libraries provide pre-designed components and styles that can be easily integrated into your application, ensuring a cohesive look and feel. Customization is still possible, but it's not forced upon you, which can speed up development.

Which of the following can be a potential pitfall when using Portals?

  • Compatibility issues with older browsers.
  • Difficulty in styling the portal content.
  • Improved accessibility.
  • Loss of event delegation.
A potential pitfall when using Portals is the loss of event delegation. Events that bubble up from the portal content may not behave as expected, especially if you rely on event delegation. Styling the portal content can be achieved, but it may require some adjustments. Improved accessibility is generally a benefit of using Portals, and compatibility issues with older browsers can be a concern but not a common pitfall.

To theme a React application using styled-components, you often use the ThemeProvider and the ______ context.

  • Color
  • Style
  • Theme
  • ThemeConfig
When theming a React application with styled-components, the common practice is to use the ThemeProvider component and the Theme context. The ThemeProvider provides access to the theme object, which contains styling information, and the Theme context makes it accessible throughout the application. So, the correct term to fill in the blank is "Theme."

In TypeScript, to define the type for the state in class components, we often use the ________.

  • state
  • props
  • constructor
  • interface
In TypeScript, we often use the interface keyword to define the type for the state in class components. An interface allows us to describe the shape of the state object, making it easier to enforce type safety and catch potential errors during development. The other options (state, props, constructor) are related to class components but do not define the type for the state.

You're building a React application that needs to fetch data from a REST API and display it. However, the API occasionally takes a long time to respond. Which feature in Axios would you use to set a maximum time before the request is aborted?

  • Connection Limit
  • Delayed Response
  • Retry
  • Timeout
In Axios, the 'timeout' feature is used to set a maximum time before a request is aborted if it takes too long to respond. This is especially useful when dealing with APIs that occasionally have slow response times to prevent indefinitely waiting for a response.