C++ Interview Preparation

This repository contains comprehensive C++ interview preparation materials focusing on language features rather than data structures and algorithms.

Project Structure

Study/
├── CMakeLists.txt          # Build configuration
├── README.md              # This file
├── build/                 # Build directory (created after cmake)
└── src/                   # Source files directory (26 numbered topics)
    ├── 01_basics.cpp
    ├── 02_pointers_references.cpp
    ├── 03_classes_objects.cpp
    └── ... (01-26 topic files total)

Building the Project

mkdir build
cd build
cmake ..
make

Running Individual Topics

Each topic can be compiled and run separately (numbered by complexity):

# Start with the fundamentals
./01_basics
./02_pointers_references
./03_classes_objects

# Progress through complexity
./10_inheritance
./21_templates
./26_multithreading

Topics Covered (Ordered by Complexity: 01-26)

All 25 files now have comprehensive implementation structures with classes, demonstration functions, and TODO implementation points.

Fundamentals (01-04)

• 01_basics.cpp - Data types, variables, functions, scope, parameter passing
• 02_pointers_references.cpp - Pointer operations, references, function pointers, pointer arithmetic
• 03_classes_objects.cpp - Constructors, destructors, Rule of 3/5, static members
• 04_const_correctness.cpp - Const variables, member functions, const parameters

Functions & Operators (05-06)

• 05_function_overloading.cpp - Overload resolution, const overloading, templates
• 06_operator_overloading.cpp - Arithmetic, comparison, stream operators, best practices

Memory & Storage (07-09)

• 07_memory_management.cpp - Stack/heap, new/delete, memory leaks, RAII principles
• 08_static_keyword.cpp - Static variables, members, linkage, initialization order
• 09_namespaces.cpp - Namespace usage, ADL, anonymous namespaces, aliases

Advanced OOP (10-14)

• 10_inheritance.cpp - Single/multiple inheritance, diamond problem, access levels
• 11_polymorphism.cpp - Runtime vs compile-time polymorphism, virtual dispatch
• 12_virtual_functions.cpp - Virtual functions, vtables, pure virtual, final keyword
• 13_friend_functions.cpp - Friend functions and classes, breaking encapsulation
• 14_casting.cpp - static_cast, dynamic_cast, const_cast, reinterpret_cast, safety

Object Semantics (15-17)

• 15_copy_semantics.cpp - Copy constructors, assignment operators, deep/shallow copy
• 16_exception_handling.cpp - try/catch, custom exceptions, exception safety, RAII
• 17_raii.cpp - Resource management, automatic cleanup, scope guards

Modern C++ (18-20)

• 18_smart_pointers.cpp - unique_ptr, shared_ptr, weak_ptr, custom deleters
• 19_move_semantics.cpp - Move constructors, perfect forwarding, RVO, rvalue references
• 20_auto_decltype.cpp - Type deduction, auto keyword, decltype, decltype(auto)

Generic Programming (21-23)

• 21_templates.cpp - Function/class templates, specialization, variadic templates, SFINAE
• 22_lambda_functions.cpp - Lambda syntax, captures, generic lambdas, closures
• 23_stl_containers.cpp - Vector, map, set, iterators, algorithms, container selection

System Level (24-26)

• 24_preprocessor.cpp - Macros, header guards, conditional compilation, alternatives
• 25_file_io.cpp - File streams, error handling, binary operations, RAII file handling
• 26_multithreading.cpp - std::thread, mutex, condition variables, atomics, synchronization

🎯 Implementation Pattern

Each file contains:

• Complete class hierarchies with realistic interview scenarios
• Comprehensive demonstration functions that showcase each concept progressively
• Specific TODO implementation points marking exactly what needs to be coded
• Progressive examples from basic to advanced usage patterns
• Interview-focused scenarios covering the most commonly asked questions

🚀 Study Approach

Recommended Learning Path:

1. Start with fundamentals (01-04) - Build solid foundation
2. Progress through numbered sequence - Each topic builds on previous ones
3. Implement TODO sections - Fill in class methods and demonstration functions
4. Test your implementations - Compile and run each executable
5. Practice explaining concepts - Prepare for verbal explanations

Build and Test Individual Topics:

# Work on specific complexity levels
make 01_basics && ./01_basics                    # Foundation
make 10_inheritance && ./10_inheritance          # OOP concepts  
make 18_smart_pointers && ./18_smart_pointers    # Modern C++
make 26_multithreading && ./26_multithreading    # Advanced topics

# Or build everything (some will have linking errors = your TODO list!)
make

Interview Focus Areas

High Priority (Most Commonly Asked) - Topics 01-17

1. Classes and Objects (03) - Constructor/destructor, Rule of 3/5/0
2. Inheritance & Polymorphism (10-12) - Virtual functions, inheritance hierarchies
3. Memory Management (07, 17, 18) - Stack vs heap, RAII, smart pointers
4. Const Correctness (04) - const member functions, const parameters
5. Move Semantics (19) - rvalue references, move constructors, perfect forwarding

Medium Priority - Topics 05-09, 13-16, 20-23

1. Function & Operator Overloading (05-06) - Overload resolution, best practices
2. Exception Handling (16) - Exception safety, RAII integration
3. Templates & STL (21, 23) - Basic template usage, container selection
4. Copy Semantics (15) - Deep vs shallow copy, assignment operators
5. Modern C++ Features (20, 22) - auto, decltype, lambdas

Advanced Topics - Topics 24-26

1. Multithreading (26) - Basic thread safety, synchronization primitives
2. System Programming (24-25) - Preprocessor, file I/O
3. Template Metaprogramming (21) - Advanced template techniques, SFINAE

📚 Study Strategy

Week 1: Foundation (01-09)

• Master basic language features and memory concepts
• Focus on getting comfortable with pointers, classes, and const correctness

Week 2: OOP Mastery (10-17)

• Deep dive into inheritance, polymorphism, and object lifecycle
• Understand RAII and exception safety patterns

Week 3: Modern C++ (18-23)

• Learn smart pointers, move semantics, and template basics
• Practice with STL containers and lambda functions

Week 4: Advanced Topics (24-26)

• Cover system-level programming and multithreading basics
• Focus on practical interview scenarios

Common Interview Questions

• Explain the difference between stack and heap
• What is RAII and why is it important?
• When would you use a virtual destructor?
• Explain move semantics and when to use it
• What's the difference between const and constexpr?
• How do smart pointers work internally?
• Explain the Rule of Three/Five/Zero

Good luck with your interview preparation!