C++ Standard Template Library (STL) — Handwritten Notes

Functions support modular programming. Advantages:

• improves readability by dividing program into parts
• enables reusability (same code used multiple times)
• easier testing and debugging
• reduces duplication and improves maintenance

Hence functions make large programs manageable.

C-style string is a char array ending with '\0' and often uses <cstring> functions like strlen. std::string is a C++ class that manages memory automatically and supports easy operations like concatenation and length using methods.

C-style strings need careful size handling; std::string is safer.

Explain class and object with example (and diagram)

A class is a blueprint/template that defines data members (properties) and member functions (behaviour). An object is an instance of a class that has actual memory.

Example:

• Class: Student (roll, name, marks)
• Objects: s1, s2 (actual students)

Class: Student
  - roll
  - name
  + show()

Objects: s1, s2

Thus, classes help model real-world entities and objects represent actual entities in memory.