Where to Find Classes The highlevel problem statements

“Where to Find Classes” • The high-level problem statements • Lower-level requirements • Expert knowledge of the problem domain • Use cases if already present Discover Classes, Some Hints by Jan Pettersen Nytun, page 1

Discover Classes Grammatical Inspection Noun: Noun a word that names or denotes something. E. g. : Fisher doesn’t know which river to choose…. Noun Phrases: Phrases E. g. : Fisher selects a seasonal fishing license… Nouns become classes/objects Fisher River Noun Phrases become attributes Fishing. License card. Type: String Discover Classes, Some Hints by Jan Pettersen Nytun, page 2

Operations and Associations Grammatical Inspection Verbs become operations Verbs: Verbs E. g. : He uses the localisation service to find the closest hotel. Locator get. Closest. Hotel() Verb Phrases: Phrases E. g. : The user can use different devices … E. g. : Fisher selects a seasonal fishing license… Verb Phrases become associations User Fisher uses ownership Device Fishing. License Discover Classes, Some Hints by Jan Pettersen Nytun, page 3

Attributes Rather Than Objects Possessive Phrase: Phrase E. g. : A fishing card has a limited duration. . . A possessive phrase indicates that the noun correspond to an attribute rather than an object (but this is not always the case - you may use composition) Fishing. Card duration Discover Classes, Some Hints by Jan Pettersen Nytun, page 4