How can we find the version of React at runtime in the browser?
Interviewer Expectations for this Question
01
Core Competency
Assesses fundamental understanding of React conventions, runtime behavior, and memory/performance considerations.
02
Evaluation Criteria
Hiring managers look for precision, avoidance of ambiguous jargon, and ability to explain trade-offs under real production conditions.
Comprehensive Model Answer
Verified Solution
You can use React.version to get the version.
```jsx harmony
const REACT_VERSION = React.version;
ReactDOM.render(
<div>{React version: ${REACT_VERSION}}</div>,
document.getElementById("app")
);
> **Modern React Note (React 18/19):** `ReactDOM.render` was deprecated in React 18 and removed in React 19. In modern applications, always use `createRoot` from `react-dom/client`:
> > import { createRoot } from 'react-dom/client';
> const root = createRoot(document.getElementById('root'));
> root.render(<App />);
> ```
Candidate Response Strategy & Interview Tips
- Start with a concise one-sentence summary: Deliver a direct, confident answer first before expanding into nuances.
- Demonstrate real-world trade-offs: Discuss where this approach excels and when you would avoid it in production systems.
- Discuss complexity & edge cases: Proactively explain time/space complexity or boundary conditions (null values, scale limits).
- Prepare for interviewer follow-ups: Technical hiring panels frequently probe deeper into concurrency, backward compatibility, or alternative libraries.