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unit 5 opps

  1️⃣ Strings in C++ 🔹 Definition (Easy Words) A string is a collection of characters used to store text like name, address, etc. Example: "Ujjwal" "ATM Machine" "Library Book" 🔹 String in C++ C++ provides string class in <string> library. #include <iostream> #include <string> using namespace std ; int main () { string name = "Ujjwal" ; cout << name ; } 🔹 Common String Operations string s1 = "Hello" ; string s2 = "World" ; cout << s1 + " " + s2 ; // Concatenation cout << s1 .length(); // Length 2️⃣ Exception Handling in C++ 🔹 Definition (Easy Words) Exception handling is a method to handle errors during program execution so the program does not crash. In simple words: 👉 If an error happens, we handle it safely. 🔹 Keywords Used try catch throw 🔹 Example #include <iostream> using namespac...
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unit 4 opps

  1️⃣ Polymorphism – Introduction 🔹 Definition Polymorphism means “many forms” . In OOP, polymorphism allows: One function or object to behave differently in different situations. 🔹 Real Life Example A person behaves differently as: Father at home Employee at office Friend in society Same person → different behavior 👉 This is polymorphism. 2️⃣ Types of Polymorphism in C++ Polymorphism is divided into: 1️⃣ Compile-Time (Static) Polymorphism 2️⃣ Run-Time (Dynamic) Polymorphism 3️⃣ Compile-Time (Static) Polymorphism It is resolved at compile time . Achieved by: Function Overloading Operator Overloading 🔹 Method (Function) Overloading Definition Same function name but: Different number of parameters OR Different type of parameters 🔹 Example in C++ #include <iostream> using namespace std ; class Calculator { public : int add( int a , int b ) { return a + b ; } double add( double a , d...
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unit 3 opps

  1️⃣ Relationships in OOP In Object-Oriented Programming, objects and classes are connected through relationships . Main types: Inheritance (IS-A) Association (Uses/Has-A) Aggregation (Has-A, weak form) Composition (strong Aggregation – optional mention) 2️⃣ Inheritance 🔹 Definition Inheritance is a mechanism by which one class acquires the properties and behavior of another class. 👉 It promotes code reusability . 🔹 Purpose of Inheritance ✅ Code Reuse ✅ Extensibility ✅ Logical hierarchy ✅ Polymorphism support ✅ Reduces redundancy 🔹 Syntax in C++ class Parent { // base class }; class Child : public Parent { // derived class }; 🔹 “IS-A” Relationship Inheritance represents an IS-A relationship . Example: Dog IS-A Animal Car IS-A Vehicle So, Dog inherits from Animal . 🔹 Example in C++ #include <iostream> using namespace std ; class Animal { public : void eat() { cout << "Animal is eati...
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ch 2 oops

  1️⃣ Encapsulation (C++) 🔹 Definition Encapsulation means wrapping data (variables) and methods (functions) together into a single unit called a class , and restricting direct access to data. 👉 Achieved using: private protected public 🔹 Why Needed? Data security Prevents unauthorized access Controls modification 🔹 Example in C++ #include <iostream> using namespace std ; class BankAccount { private : double balance; // Hidden data public : void deposit( double amount ) { balance += amount ; } double getBalance() { return balance ; } }; int main () { BankAccount obj ; obj .deposit( 5000 ); cout << obj .getBalance(); } ✅ balance cannot be accessed directly. This is data hiding + encapsulation . 2️⃣ Data Abstraction (C++) 🔹 Definition Abstraction means hiding internal implementation details and showing only essential features. 👉 Real Example: ATM machine — you pre...
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