Update setTimeout() and setInterval() Return Value Description with Numeric Range and Clarification

[low-perry]

Description

This pull request updates the description of the return value for setTimeout() and seInterval() to clarify exactly what the returned timeout/interval identifier is—as well as to include its typical numeric range.

• Numeric Range: Added a parenthesized note to indicate the typical numeric range of the timeout ID/ interval ID, providing developers with an expectation of its value.

• Clarification of the Timeout/ Interval Identifier: Defined the terms "timeoutId"/"intervalId" clearly as the unique identifier returned by setTimeout()/setInterval().

• ID Pool Clarification: Revised the language regarding the reuse of IDs by replacing “different objects” with “distinct global environments” and clarifying that each global environment (e.g., windows, iframes, workers) maintains its own separate pool of timer IDs.

Motivation

Including the numeric range information improves clarity on what developers can expect in terms of the possible values.
Explicitly defining the timeout identifier and clarifying the ID pool explanation helps prevent confusion about when and where these identifiers might be reused.

Additional details

Related issues and pull requests

Fixes #39004

[github-actions]

Preview URLs

• /en-US/docs/Web/API/Window/setInterval
• /en-US/docs/Web/API/Window/setTimeout
• /en-US/docs/Web/API/WorkerGlobalScope/setInterval
• /en-US/docs/Web/API/WorkerGlobalScope/setTimeout

(comment last updated: 2025-04-08 01:09:23)

[low-perry]

I think similar changes can also be included on the setInterval() method.

[Josh-Cena]

I think similar changes can also be included on the setInterval() method.

Feel free to

[low-perry]

Feel free to

I revised the overview paragraph for the setInterval() method, removing the return value to ensure consistency with the setTimeout() overview section. Additionally, I updated the return value description for setInterval() in both the Window interface and WorkerGlobalScope interface for clarity and alignment.