➕ Function and Operator Overloading in C++

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🎯 Aim

To study and implement Function Overloading and Operator Overloading in C++.

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📚 Theory

In C++, overloading is a fundamental feature of polymorphism that allows the same function or operator to perform different tasks depending on the context. This makes programs more intuitive, flexible, and closer to natural language.

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🔹 Function Overloading

Function overloading allows multiple functions with the same name but different parameter lists. The compiler decides which version to call at compile time based on the number and types of arguments.

Key Characteristics:

• Functions must differ in the number or type of parameters.
• Return type alone cannot distinguish overloaded functions.
• Represents compile‑time polymorphism (static binding).
• Improves readability by grouping logically similar operations under one name.

Advantages:

• Simplifies code by avoiding multiple function names for similar tasks.
• Makes programs easier to understand and maintain.
• Provides flexibility in handling different data types and argument counts.

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🔹 Operator Overloading

Operator overloading allows redefining the behavior of operators (+, -, *, etc.) for user‑defined types (classes). This enables objects to behave like built‑in types, allowing natural expressions such as c1 + c2 for complex numbers.

Key Characteristics:

• Declared using the keyword operator.
• Can be implemented as a member function or friend function.
• Some operators (::, ., .*, ?:) cannot be overloaded.
• Enhances readability and abstraction by allowing intuitive operations on objects.

Advantages:

• Makes user‑defined types more expressive.
• Allows natural mathematical and logical operations on objects.
• Improves code clarity and reduces verbosity.

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📋 Algorithms

🧾 Function Overloading (Addition Class)

1. Start
2. Define a class Addition.
3. Inside the class, define three overloaded methods:
   • sum(int a, int b) → returns sum of two integers.
   • sum(int a, int b, int c) → returns sum of three integers.
   • sum(double d, double e) → returns sum of two doubles.
4. In main():
   • Create an object obj.
   • Call obj.sum(10,20) → invokes 2‑int version.
   • Call obj.sum(10,20,20) → invokes 3‑int version.
   • Call obj.sum(10.8,20.34) → invokes 2‑double version.
   • Display results.
5. End

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🧾 Function Overloading (UserInfo Class)

1. Start
2. Define a class UserInfo.
3. Overload the method show() with different parameter lists:
   • show(string name) → prints only name.
   • show(string name, int age) → prints name and age.
   • show(string name, string city) → prints name and city.
   • show(string name, int age, string city) → prints all three.
4. In main():
   • Create an object u.
   • Call each overloaded version with appropriate arguments.
   • Display results.
5. End

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🧾 Operator Overloading (Complex Numbers)

1. Start
2. Define a class Complex with members real, imag.
3. Create a constructor to initialize values.
4. Overload the + operator:
   • Add real parts.
   • Add imaginary parts.
   • Return a new Complex object.
5. Define a display() method to print the result.
6. In main():
   • Create two objects c1, c2.
   • Compute c3 = c1 + c2.
   • Display c3.
7. End

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🧾 Operator Overloading (Book Class)

1. Start
2. Define a class Book with members title, pages.
3. Create a constructor to initialize values.
4. Overload the - operator:
   • Concatenate titles with " & ".
   • Add page counts.
   • Return a new Book object.
5. Define a display() method to print details.
6. In main():
   • Create two objects b1, b2.
   • Compute b3 = b1 - b2.
   • Display all three books.
7. End

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🧠 Conclusion

This experiment demonstrates the versatility of overloading in C++:

• Function Overloading → Same function name, different parameter lists, enabling flexible and intuitive use of functions.
• Operator Overloading → Redefines operators for user‑defined types, making objects behave like built‑in types.
• Both are examples of compile‑time polymorphism, resolved by the compiler before execution.
• Overloading improves readability, reusability, and abstraction, making programs more expressive and easier to maintain.