Lecture on C Programming

Introduction

• Instructor: Father Manodar, a software developer at Programmies.
• Series on C Programming aims to provide a strong foundation in C and programming in general.

What is C Programming?

• C is a general-purpose programming language created in the 1970s.
• Initially developed to rewrite the UNIX operating system.
• Used in modern applications like web browsers (Google Chrome, Firefox) and databases (MySQL).
• Despite new languages like Python and JavaScript, C remains relevant.
• C is valued for its speed, efficiency, and ability to access hardware at a low level.
• High demand for C programmers with 18,000 job openings in the US (source: Glassdoor).
• Many universities teach C as the first programming language.

Learning C Programming

• Understanding C helps in understanding the interaction between software and hardware.
• C programming is recommended for a deeper understanding of programming basics.
• Programmies offers an online tool to run C programs without installation.

Writing a Simple C Program

• Example: "Hello, World!" program.
• Structure of a C program includes:
  • int main() function as the starting point.
  • #include <stdio.h> to include standard input-output functions.
  • printf() function for output.

Variables in C

• A variable is a named memory location to store data.
• Declaration and initialization of variables.
• Example with int data type.
• Format specifiers like %d for integers.
• Changing and updating variable values.

Data Types in C

• Common data types: int, float, double, char.
• Use sizeof operator to find the size of data types.
• Print characters, integers, and floating-point numbers using format specifiers.

Input in C

• Use scanf() for input from the user.
• Format specifiers in scanf() similar to printf().

Comments in C

• Single-line comments start with //.
• Multi-line comments enclosed in /* ... */.
• Comments improve code readability and are useful for debugging.

Operators in C

• Arithmetic operators: +, -, *, /, %.
• Increment (++) and decrement (--) operators.
• Precedence and associativity rules for operator execution.

Type Conversion

• Implicit and explicit type conversion in C.
• Use of typecasting for explicit conversion.

Boolean and Logical Operators

• Boolean values represented by 0 (false) and 1 (true).
• Comparison operators: ==, !=, <, >, <=, >=.
• Logical operators: && (AND), || (OR), ! (NOT).

Control Flow

• If-Else Statements: Make decisions based on conditions.
• Ternary Operator: A shorthand for simple if-else conditions.
• Switch Statement: Used for selecting among multiple options.

Loops in C

• While Loop: Repeats a block of code while a condition is true.
• Do-While Loop: Executes a block first, then checks the condition.
• For Loop: Repeats a block a specific number of times.
• Break and Continue: Used to alter loop execution flow.

Functions in C

• Functions divide a program into smaller, manageable parts.
• Function declaration, definition, and calling.
• Return types and parameters in functions.
• Standard library functions (e.g., printf, scanf) and user-defined functions.

Pointers

• Pointers store memory addresses of variables.
• Use * to define and dereference pointers.
• Arrays and pointers, accessing array elements using pointers.
• Pointers and functions: passing addresses to functions.

Structs in C

• Structs group different types of variables under a single name.
• Dot operator to access struct members.

Enums

• Enum is a user-defined type consisting of named integer constants.

Dynamic Memory Allocation

• malloc, calloc, realloc, free for managing memory during runtime.

File Handling

• Open, read/write, and close files using fopen, fclose, fgets, fputs.

Preprocessors and Macros

• Preprocessors are directives that are processed before compilation.
• Common preprocessors: #include, #define.
• Macros are defined using #define for constant values or functions.

Conclusion

• C programming provides a strong foundation for understanding software and hardware interactions.
• Practice by writing and executing programs to reinforce learning.