C Programming Course Notes

Overview of C Programming

• C is one of the oldest programming languages.
• Learning C provides a good foundation for modern languages like C++.
• The course aims to cover:
  • Installing a text editor and C compiler
  • Writing basic C code
  • Core concepts like statements, loops, variables, functions, and pointers.

Setting Up the C Programming Environment

Required Tools

1. Text Editor or IDE (Integrated Development Environment)
   • Recommended IDE: Code::Blocks.
2. C Compiler
   • GNU GCC Compiler included with Code::Blocks.

Installation Steps for Code::Blocks

1. Search for "Code::Blocks C" in the web browser.
2. Download the binary release applicable to your OS.
3. Follow the installation prompts to set up Code::Blocks and GCC Compiler.

Basic Code Structure in C

• Every C program has a main function.
• A simple program structure:

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

Writing Your First C Program

Writing Code

• The printf function is used to print output to the console.
• To execute code, the program must be built and run.

Compiling and Running Code

• Use the "Build and Run" option in Code::Blocks to execute your program.

Basic Concepts in C

Variables

• Variables are containers for storing data values.
• Types of variables include integers, doubles, and characters.
• Syntax for declaring variables:

  int age;
  double gpa;
  char grade;
  

Data Types

• Basic data types:
  • int: Integer numbers.
  • double: Decimal numbers.
  • char: Single characters.
• char[] is used for strings (e.g., arrays of characters).

Control Structures

If Statements

• Used to make decisions based on conditions.
• Syntax:

  if (condition) {
      // code to execute if true
  } else {
      // code to execute if false
  }
  

Switch Statements

• A cleaner alternative to multiple if statements for comparing one variable against different values.
• Syntax:

  switch (variable) {
      case value1:
          // code
          break;
      case value2:
          // code
          break;
      default:
          // code
  }
  

Loops

While Loops

• Used for repeatedly executing a block of code as long as a condition is true.
• Syntax:

  while (condition) {
      // code to execute
  }
  

For Loops

• A more compact way to express a loop, particularly when using an indexing variable.
• Syntax:

  for (initialization; condition; increment) {
      // code to execute
  }
  

Functions

• Functions are blocks of code that perform specific tasks.
• Can accept parameters and return values.
• Syntax:

  returnType functionName(parameters) {
      // code
      return value;
  }
  

Structs

• Structs allow grouping of different data types under a single name.
• Useful for representing complex data structures like a student with attributes (name, age).
• Syntax:

  struct Student {
      char name[50];
      int age;
      double gpa;
  };
  

Pointers

• Pointers store memory addresses of other variables.
• Syntax for declaring a pointer:

  int *ptr;
  

• Dereferencing pointers to access the value at the memory address:

  printf("%d", *ptr);
  

File I/O

• Reading and writing files using functions like fopen, fprintf, and fgets.
• Modes include:
  • r: Read
  • w: Write (overwrites existing files)
  • a: Append (adds to end of file)
• Example of writing to a file:

  FILE *fp;
  fp = fopen("file.txt", "w");
  fprintf(fp, "Hello, World!");
  fclose(fp);
  

• Example of reading from a file:

  FILE *fp;
  fp = fopen("file.txt", "r");
  fgets(line, sizeof(line), fp);
  fclose(fp);
  

Summary

• Following the course will provide a solid foundation in C programming.
• Key concepts include variables, control structures, functions, structs, pointers, and file I/O.
• Practice using each concept to solidify understanding.