OOP in practice

Apply OOP to real projects and interviews.

📖 Key ideas

Model a domain: Library (Book, Member, Loan), Bank (Account, Customer, Transaction).
Identify nouns (classes) and verbs (methods) from requirements.
Use design patterns for common problems.
Write unit tests for classes.
OOP questions are common in interviews: pillars, overloading vs overriding, abstract vs interface.

💡 Real-life example: OOP design is casting a play: choose the characters (classes) and their dialogues (methods).

Domain modelClasses representing real concepts

Noun-verb analysisFinding classes and methods from text

Design patternReusable solution template

Unit testTest for a class/method