Implement random.choice()

[Smoren]

Generate random selections from an array of values.

If optional param repetitions not given then iterate infinitely.

function *choice<T>(items: Array<T>, repetitions?: number): Iterable<T>

PHP implementation example

Needs to be implemented:

• random.choice()
• random.choiceAsync()
• Stream.choice()
• AsyncStream.choice()

[Seedname]

Implemented in PR #94