Why we need to be careful when spreading props on DOM elements?
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
When we _spread props_ we run into the risk of adding unknown HTML attributes, which is a bad practice. Instead we can use prop destructuring with ...rest operator, so it will add only required props.
For example,
```jsx harmony
const ComponentA = () => (
<ComponentB isDisplay={true} className={"componentStyle"} />
);
const ComponentB = ({ isDisplay, ...domProps }) => (
<div {...domProps}>{"ComponentB"}</div>
);
```
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.