Swift Cheat Sheet 2026

The 30 highest-yield Swift facts, distilled from real exam questions. Print it, save it as a PDF, or study it here — free, no sign-up.

1. What is the best way to describe an algorithm? → A step-by-step series of operations
2. Which SWIFT service allows banks to confirm whether a beneficiary account is active and matches the expected name before sending a payment? → Pre-validation
3. What is the maximum length of a SWIFT BIC (Business Identifier Code)? → 11 characters
4. Which approach best demonstrates professional competency in Swift practice? → Integrating continuing education, practical experience, and evidence-based decision making
5. You're refactoring a legacy codebase where many functions return `-1` to signal errors. Which modern Swift pattern replaces this anti-pattern? → Returning `Int?` with nil for errors, or throwing a typed Error
6. Which ISO 20022 message replaces the MT 202 financial institution credit transfer? → pacs.009
7. A `Result` is returned from a fetch function. You need to map each post's title to uppercase on success. Which approach is most concise? → `result.map { posts in posts.map { $0.title.uppercased() } }`
8. Under Swift's Know Your Customer (KYC) Registry, what is the primary purpose of the KYC Registry service? → To centralize and standardize correspondent banking due diligence documentation
9. What is snapshot testing in Swift iOS development primarily used for? → Capturing and comparing UI renderings to detect visual regressions
10. In Swift, what is a `protocol` with an `associatedtype` primarily used for? → Defining generic interfaces that work with placeholder types
11. Which assertion in XCTest verifies that two values are NOT equal? → XCTAssertNotEqual
12. Why is Swift good for game development? → B & D
13. What is a Swift `protocol` with an associated type commonly used for? → Creating generic abstractions that work with multiple conforming types
14. What does a SWIFT Business Continuity (BC) plan specifically need to address for messaging infrastructure? → Redundant SWIFT connectivity and failover procedures for service restoration
15. Which organization serves as the Registration Authority for the ISO 20022 standard? → SWIFT
16. What is SWIFT gpi (Global Payments Innovation) designed to improve? → Speed, transparency, and tracking of cross-border payments
17. Which level of measurement allows for meaningful ratios (e.g., 'twice as much') and has a true zero point? → Ratio
18. Which ISO 20022 messages replace MT 940, MT 941, and MT 942 for account balance and transaction reporting? → camt.052, camt.053, and camt.054
19. A payment operations team notices an increase in returned SWIFT payments from a specific corridor. What is the first stakeholder communication step? → Notify senior management and the correspondent bank with supporting data
20. In ISO 20022 pacs messages, what does the 'InstructedAmount' field represent? → The original amount instructed by the debtor before any charges or conversion
21. What is the recommended way to test asynchronous Swift code using async/await in XCTest? → Mark the test function as async and use await directly
22. In XCTest performance testing, what does 'measure {}' do? → Runs the block multiple times and records execution time metrics
23. How should an Swift professional respond to a compliance violation? → Report it promptly, investigate the root cause, and implement corrective actions
24. What exactly is coding? → Telling a ​computer what to do.
25. In Swift UI testing with XCTest, which class is used to represent and interact with the running application? → XCUIApplication
26. You want SwiftUI's `ProfileView` to automatically re-render when `user.name` changes. `User` is a reference type shared across views. What is the correct setup? → Make `User` a class conforming to `ObservableObject` with `@Published var name`
27. Which professional competency is most critical when implementing Swift ISO 20022 migration changes in a live production environment? → Thorough testing, change management protocols, and fallback planning
28. Effect size in research is important because it indicates: → The practical magnitude of an observed difference or relationship
29. Which service on SWIFTNet is used for store-and-forward messaging (such as MT messages)? → FIN (Financial Application)
30. What is reflective practice in Swift professional development? → Systematically examining experiences to gain insight and improve future practice