Lesson 13: Constructors, Destructors (~), Initializer Lists & 'this' Pointer

🏗️ Object Lifecycle Management

Constructors initialize objects when created, while Destructors clean up resources (closing files, releasing Heap memory) when objects are destroyed.

🛠️ Key Concepts

⚙️ Parameterized Constructor: Initializes object fields at instantiation.

🚀 Member Initializer List (ClassName() : field1(val) {}): Fastest way to initialize class data members directly.

🧹 Destructor (~ClassName()): Has no return type and takes no arguments. Executed when object goes out of scope.

👈 this Pointer: Implicit pointer available inside member functions holding the address of the current object.

💻 Code Example: RAII Buffer Allocation Class

⊞C++ Source Code (main.cpp)

#include <iostream>

class DynamicBuffer {

private:

int *data;

int size;

public:

// Constructor with Member Initializer List

DynamicBuffer(int s) : size(s), data(new int[s]) {

std::cout << "🏗️ Allocated buffer of size " << size << " on Heap." << std::endl;

}

// Destructor (RAII Resource Cleanup)

~DynamicBuffer() {

delete[] data;

std::cout << "🧹 Destructor freed Heap memory buffer." << std::endl;

}

};

int main() {

{

DynamicBuffer buf(1024); // Object scope begins

} // Object goes out of scope here -> Destructor fires automatically!

return 0;

}

⊞Windows 11 Pro Terminal Execution OutputWindows 11 Pro Verified

⊞Administrator: Windows 11 Pro Command Prompt (g++ GCC 13.2.0)

—□✕

Microsoft Windows [Version 10.0.22631.3007] (Windows 11 Pro x86_64)

C:\Users\Student\CPP_Project>#include <iostream>

C:\Users\Student\CPP_Project> g++ -o main.exe main.cpp C:\Users\Student\CPP_Project> main.exe Hello World from C++ on Windows 11 Pro! [Process exited with code 0 in 0.001 seconds]

🏗️ Object Lifecycle Management

🛠️ Key Concepts

💻 Code Example: RAII Buffer Allocation Class

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