seq.forEach()

⛔ break : not allowed.
⛔ continue : not allowed.
❗ return : exit only from the current call to body. 👉 1️

// `seq.forEach(_:)` declaration:
func forEach(
    _ body: (Self.Element) throws -> Void
) rethrows

// sequence.forEach()
(1...10).forEach { n in 
    print(n)
    // ⭐️ return from this closure, not from the `forEach` method
    if n > 2 { return } 
}
// 1, 2, ..., 10

class ArticleGroupViewController: UIViewController {

    private let articles: [Article]

    override func viewDidLoad() {
        super.viewDidLoad()
        
        // ⭐️ 直接將 method 放入 forEach()，可增加程式的可讀性。
        articles.forEach(addArticleView)
    }

    private func addArticleView(for article: Article) {
        let articleView = ArticleView()
        view.addSubview(articleView)
    }
}

forEach vs. for-in loop

PreviousSequence Nextseq.reduce(_:_:)

Last updated 3 years ago

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