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React Star Rating Widget

By FrontendAtlas Team · Updated Jan 30, 2026

Implement a reusable widget in React. It should render a row of clickable stars, allow the user to select a rating, and notify a parent component when the rating changes. React focus: build a controlled component and notify parent on change. Framework focus: React hooks…

Render a component as part of the main UI.
Display a row of stars (e.g. 5 by default).

What you’ll build / What this tests

This premium react coding focuses on React Star Rating Widget. You’ll apply react and state thinking with easy level constraints. The prompt emphasizes Implement a reusable widget in React. It should render a row of clickable stars, allow the….

Learning goals

Translate the prompt into a clear react API signature and return shape.
Apply react, state, props techniques to implement react star rating widget.
Handle easy edge cases without sacrificing readability.
Reason about time/space complexity and trade-offs in react.

Key decisions to discuss

Define the exact input/output contract before coding.
Prioritize predictable edge-case handling over micro-optimizations.

Evaluation rubric

Correctness: covers required behaviors and edge cases.
Clarity: readable structure and predictable control flow.
Complexity: avoids unnecessary work for large inputs.
API discipline: no mutation of inputs; returns expected shape.
Testability: solution is easy to unit test.

Constraints / Requirements

Render a component as part of the main UI.
Display a row of stars (e.g. 5 by default).
Allow the parent to control the current rating via props.
Notify the parent when the user selects a new rating (e.g. via an onChange callback).
Display the current rating value below the stars.
Stars render from 1 up to the configured max (default 5).
Clicking the 3rd star sets the rating to 3 (and fills 3 stars).
Clicking the 5th star sets the rating to 5 (and fills 5 stars).
Updating the rating in the parent reflects in the UI.
Keep as a controlled component: it receives rating and onChange props.

Mini snippet (usage only)

// Example usage
const input = /* react star rating widget input */;
const result = solve(input);
console.log(result);

// Edge case check
const empty = input ?? null;
const fallback = solve(input);
console.log(fallback);

// Expected: describe output shape, not the implementation
// (no solution code in preview)

Common pitfalls

Mutating inputs instead of returning a new value.
Skipping edge cases like empty input, duplicates, or nulls.
Overlooking time complexity for large inputs.