readme.md

S.Leschev Design Patterns (Swift 5+)

Google Engineering Level: L6+

🏆 Awards

Ranking #Dev: Global TOP 300 (Certificate)

Languages: Swift, Shell, Database (T-SQL, PL/SQL, MySQL), Concurrency (Python3).

Algorithms: linked lists, binary search, hash table, queue/stack, dfs/bfs, sort, heap/hash, two pointers, sliding window, tree, greedy problems etc.

🏭 Factory Method

The factory pattern is used to replace class constructors, abstracting the process of object generation so that the type of the object instantiated can be determined at run-time.

Example

protocol CurrencyDescribing {
    var symbol: String { get }
    var code: String { get }
}

final class Euro: CurrencyDescribing {
    var symbol: String {
        return "€"
    }
    
    var code: String {
        return "EUR"
    }
}

final class UnitedStatesDolar: CurrencyDescribing {
    var symbol: String {
        return "$"
    }
    
    var code: String {
        return "USD"
    }
}

enum Country {
    case unitedStates
    case spain
    case uk
    case greece
}

enum CurrencyFactory {
    static func currency(for country: Country) -> CurrencyDescribing? {

        switch country {
            case .spain, .greece:
                return Euro()
            case .unitedStates:
                return UnitedStatesDolar()
            default:
                return nil
        }
        
    }
}

Usage

let noCurrencyCode = "No Currency Code Available"

CurrencyFactory.currency(for: .greece)?.code ?? noCurrencyCode
CurrencyFactory.currency(for: .spain)?.code ?? noCurrencyCode
CurrencyFactory.currency(for: .unitedStates)?.code ?? noCurrencyCode
CurrencyFactory.currency(for: .uk)?.code ?? noCurrencyCode

Contacts

I have a clear focus on time-to-market and don't prioritize technical debt.

🛩️ #startups #management #cto #swift #typescript #database

📧 Email: sergey.leschev@gmail.com

👋 LinkedIn: https://linkedin.com/in/sergeyleschev

👋 Twitter: https://twitter.com/sergeyleschev

👋 Github: https://github.com/sergeyleschev

🌎 Website: https://sergeyleschev.github.io

🖨️ PDF: Download

ALT: SIARHEI LIASHCHOU