Correction to Iterator.prototype.flatMap()'s callback return type

[mb21]

Description

Correction to Iterator.prototype.flatMap()'s callback return type, which always needs to be an iterator. E.g this does not work (check in Chrome or using a polyfill):

[1, 2, 3].values().flatMap(num => num === 2 ? [2, 2] : 1).toArray()

Motivation

motivated by https://github.com/tc39/proposal-iterator-helpers/issues/275#issuecomment-2098790245

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Preview URLs

• /en-US/docs/Web/JavaScript/Reference/Global_Objects/Iterator/flatMap

(comment last updated: 2024-05-19 13:32:53)