reactjs / reactjs/react.dev

[Bug]: Next button throws a runtime error instead of cycling to the first sculpture

Open Beginner friendly
#8,634 3 comments 0 reactions 0 assignees View on GitHub

Nobody has claimed this yet.

bug: unconfirmed
Dominant language
JavaScript
Stars
11.8k
Forks
7.9k
Avg merge
1d 11h
Merged PRs (30d)
11

Description

Summary

On the State: A Component's Memory page, the Sculpture Gallery example allows users to navigate through sculptures using the Next button. The gallery works correctly while navigating through valid entries, but when the user clicks Next on the final sculpture (12 of 12), the application does not cycle back to the first sculpture.

Instead, the index exceeds the sculpture list bounds, making sculpture undefined and causing the runtime error:

App.js: can't access property "name", sculpture is undefined

Expected: The gallery should wrap around from the last sculpture to the first sculpture when Next is clicked.

Actual: The application throws a runtime error because it attempts to access properties such as sculpture.name on an undefined object.

Affected screen: React.dev → Learn React → Adding Interactivity → State: A Component's Memory → Sculpture Gallery example.

Image Image
Page

https://react.dev/learn/state-a-components-memory

Details

No response

Contributor guide

Open the contributing guide

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Open the State: A Component's Memory page and inspect the Sculpture Gallery example, then reproduce the error by clicking Next on sculpture 12 of 12. Trace the example's index update and verify that the gallery returns to the first sculpture without accessing an undefined entry.

Written by the indexing model from the issue text.

Assessment

Tech stack
javascript, react
Domain
documentation, frontend
Issue type
Bug
Difficulty
2/5
Estimated time
1-3 hours
Activity status
Active
Clarity
Mostly clear
Newbie friendliness
74/100

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.