How Do You Use useRef to Access a DOM Element in React? Give an example.
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
The useRef hook is commonly used in React to directly reference and interact with DOM elements — like focusing an input, scrolling to a section, or controlling media elements.
When you assign a ref to a DOM element using useRef, React gives you access to the underlying DOM node via the .current property of the ref object.
Example: Focus an input
import React, { useRef } from 'react';
function FocusInput() {
const inputRef = useRef(null); // create the ref
const handleFocus = () => {
inputRef.current.focus(); // access DOM element and focus it
};
return (
<div>
<input type="text" ref={inputRef} />
<button onClick={handleFocus}>Focus the input</button>
</div>
);
}
Note: The DOM reference is only available after the component has mounted — typically accessed in useEffect or event handlers.
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.