Design Patterns

Singleton, factory, observer and strategy, as answers to problems rather than a list.

0 of 21 answered

• Not triedHiding where the data livesFoundation
• Not triedOne change, many reactionsFoundation
• Not triedOne entry point to a subsystemFoundation
• Not triedPassing dependencies inFoundation
• Not triedSwapping an algorithmFoundation
• Not triedTwo interfaces that do not matchFoundation
• Not triedWhat a design pattern isFoundation
• Not triedWhat a singleton costsFoundation
• Not triedWhy a factoryFoundation
• Not triedWhy the model knows nothing about the viewFoundation
• Not triedA constructor with too many parametersCore
• Not triedThe switch that grows every quarterCore
• Not triedWhen a factory is worth the extra classCore
• Not triedWhen a pattern makes it worseCore
• Not triedWrapping a third-party libraryCore
• Not triedA fixed sequence with variable stepsChallenge
• Not triedAdding behaviour without subclassingChallenge
• Not triedAn action as an objectChallenge
• Not triedAn object that does nothingChallenge
• Not triedThe listener nobody removedChallenge
• Not triedWhat making it a singleton cost youChallenge