Object Oriented Programming with C++ 2e (Sahay, Sourav)（Z-Library）

【One-Line Pitch】 A patient, example-driven introduction to C++ that starts from C-style structures and builds up to classes, inheritance, templates, and exception handling. Best for beginners and self-taught programmers who want to understand *why* object orientation exists, not just its syntax. 【Book Arc】 - **Opening (~0%–10%)**: Starts from procedure-oriented programming and C structures, showing why grouping related data into a new type matters, then introduces console I/O, reference variables, function prototyping, overloading, default arguments, and inline functions. - **Early (~10%–32%)**: Moves into classes and objects — private/public members, the `this` pointer, data abstraction, static members, friend functions, nested classes, and namespaces as a cure for global-name collisions. - **Middle (~32%–48%)**: Covers dynamic memory with `new`/`delete` and the danger of memory leaks, then constructors and destructors, including parameterized constructors for classes that manage resources such as strings. - **Late (~48%–70%)**: Introduces inheritance — base and derived classes, object layout, and the rules for base-class versus derived-class pointers. - **Ending (~70%–100%)**: The excerpts do not cover the closing chapters in detail, but the blurb indicates dynamic polymorphism, operator overloading, stream handling, templates and the STL, and exception handling. 【Key Takeaways】 - **Structures are the bridge from procedural to object-oriented thinking** (Opening): the book first shows how a `struct date` prevents unrelated variables from being passed to a function, then generalizes that idea into classes. - **Compile-time safety is a central argument for C++ over C** (Early): private members make invalid access a compile error rather than a silent runtime bug, which the author repeatedly frames as the practical payoff of encapsulation. - **The `this` pointer explains how member functions actually work** (Early): calls like `d1.add(d2)` are rewritten by the compiler to pass the object's address, making method dispatch concrete rather than magical. - **Namespaces solve real-world name pollution** (Early): when two headers define a class with the same name, wrapping each in its own namespace lets both coexist — a practical lesson for large programs. - **Dynamic memory demands discipline** (Middle): `new` allocates on the heap, but if the only pointer goes out of scope without `delete`, the block becomes an unreachable memory leak. - **Constructors do not allocate memory** (Middle): they are called automatically after memory is allocated, for both stack and heap objects, and the compiler supplies a do-nothing default when none is defined. - **Inheritance changes object size and pointer rules** (Late): a derived object contains its base-class data, a base pointer can point to a derived object, but the reverse conversion is rejected by the compiler. - **Inline functions are safer than macros** (Early): the `CUBE` macro example shows how text substitution breaks with expressions and `x++`, while an inline function evaluates its argument once. 【Reading Tips】 - **Deep-read the early chapters on structures, classes, and `this`** — they carry the conceptual load for everything later; skimming here makes inheritance and polymorphism feel arbitrary. - **Work through the memory diagrams and listings** rather than reading them passively; the book teaches through small, compilable examples and their compiler-transformed equivalents. - **Treat the constructor/destructor and `new`/`delete` chapters as the practical core** — this is where bugs in real C++ programs originate, and the book's memory-leak walkthrough is worth slowing down for. - **Skim the review questions if you already know C**, but use them to check whether you can explain *why* static members must be defined outside the class or why friend functions do not violate OOP principles. - **Keep a compiler open** — the book's claims about compile-time errors versus runtime errors are best verified by deliberately writing the invalid accesses it warns about. 【Coverage Limits】 This guide is based on stratified excerpts covering roughly the first half of the book; the later chapters on polymorphism, operator overloading, streams, templates/STL, and exception handling are described only at the blurb level and are not detailed here.