Object-Oriented Programming with C++: Understanding Objects, Classes, and Bank Accounts - , Study notes of Engineering

Download Object-Oriented Programming with C++: Understanding Objects, Classes, and Bank Accounts - and more Study notes Engineering in PDF only on Docsity! CSE294B Object-Oriented C++ Programming for Engineers Lecture #5 Jeffrey Miller, Ph.D. Object Analogy • To drive a car, you need the accelerator pedal, the brake pedal, the steering wheel, and the ignition (at minimum) • But what actually happens when you turn the key in the ignition? M d i d k b h d d– ost r vers o not now, ut t ey o not nee to know to be able to drive the car • This is the idea behind objects – The code that uses the object knows what the function will do, but does not need to know how it does it Bank Account Object • What is the data that is associated with a bank account? – Name A t N b– ccoun um er – Balance – PIN • What are the functions that can be performed on a bank account? Deposit– – Withdrawal – Transfer – Check Balance – Change PIN Bank Account Class class Bank_Account { private: int account_number, pin; double balance; char *name; public: void set_balance(double bal) { balance = bal; } double get_balance () { return balance; } void withdraw(double amount) { balance -= amount; } }; void main() { Bank_Account ba; ba.set_balance(2000.00); ba.withdraw(100.00); } Access Specifiers • There are two access specifiers in C++ – public i t– pr va e • If a variable or function is declared public, any other piece of code can access the variable or function • If a variable or function is declared private, only the class in which that variable or function is declared can access it l f h b id h d d h• Ru e o T um – H e t e ata an expose t e necessary functions