Notes on C++ Programming

Introduction to C++ Language

• C++ is a low-level language allowing data manipulation that computers use (bits, bytes, addresses).
• General-purpose programming language conducive for scientific and management applications.
• Examples of applications written in C/C++: Microsoft Word and Excel.
• Introduced modular programming using several modules (modules represented as .c files).

Development Cycle Model

• The development of C++ programs follows a structured cycle which includes:
  • Editing/Correction of Source Code
  • Compilation Process
  • Testing

Structure of a C++ Program

• Basic structure of a C++ program demonstrated in main.c:

  #include <stdio.h>
  #include <stdlib.h>
  int main() {
      printf("Hello World!\n");
      system("PAUSE");
      return 0;
  }

• Components:
  • Include Directives: Tell the preprocessor to include standard library headers (e.g., stdio.h for I/O functions).
  • Main Function: Execution starts and ends in int main(). The opening brace { marks the beginning of instructions.
  • Return Statement: return 0; signifies successful execution.

Comments in C++

• Comments enhance documentation and maintenance for developers.
• Two forms:
  • Single-line: // comment
  • Multi-line: /* comment */

Variable Declaration

• A variable must be declared before use.
  • Syntax: Type variable_name [= value];
  • Common Types:
  • int: Integer type
  • float: Floating-point type
  • bool: Boolean type
  • char: Character type
  • char variable[n]: String (character array)

Assignment Statement

• Assigning values to a variable:

  Variable = expression;

• Common Arithmetic Operators:
  • + : addition
  • - : subtraction
  • * : multiplication
  • / : division
  • % : modulo

Input/Output Operations

• Input can be handled as follows:
  • Using scanf() from stdio.h:
    cpp scanf("formats", &variable); // where formats can be %d, %f, %c, %s
  • Using cin from iostream.h:
    cpp cin >> variable;
  • Output can be handled similarly:
  • Using printf():
    cpp printf("formats", variable);
  • Using cout:
    cpp cout << variable;

Conditional Structures

• Simple Conditional Statement:

  if (expression) {
      // Instructions
  }

• Alternative Conditional Statement:

  if (expression) {
      // Instructions1
  } else {
      // Instructions2
  }

Looping Constructs

1. Counting Loop (for loop):

   for(expr1; expr2; expr3) {
       // Instructions
   }

• expr1: Initialized once at the beginning.
• expr2: Checked before each iteration (if true, continues).
• expr3: Modified after each iteration.

1. Conditional Loop (while loop):

   while (expression) {
       // Instructions
   }

3. Post-test Loop (do-while loop):

   do {
       // Instructions
   } while (expression);

Additional Programming Tasks

• Example exercises to implement basic C programs:
  1. Write a program that calculates circle properties given a radius.
  2. Implement a temperature conversion program from Fahrenheit to Celsius.
  3. Create a program that evaluates if a number is even or odd.
  4. Develop a billing program considering various conditions for discounts.
  • Emphasis on systematic approach to problem-solving using programming logic and structures.