1. What Is Programming?

Programming is the process of creating instructions that tell a
computer how to perform a task or solve a problem.

2. What Is a Programming Language?

A programming language is a structured system used to write
instructions that can be translated and executed by a computer.

3. What Is C Programming?

C is a general-purpose programming language that gives programmers a
powerful combination of performance, efficiency and control over system
resources.

4. A Brief History of C

C has played an important role in the development of modern computing
and has influenced many programming languages used by developers today.

5. What Is Source Code?

Source code is the human-readable set of instructions written by a
programmer using a programming language.

#include <stdio.h>

int main() {

    printf("Welcome to Hadi W3B");

    return 0;
}

A programmer can read and understand the structure of this code.
However, the computer processor cannot directly execute the
English-like instructions in this form.

6. What Is a Compiler?

A compiler translates source code into a form that the computer can
process and execute.

7. What Is an IDE?

An IDE, or Integrated Development Environment, combines the main tools
needed to create, compile, run and debug programs.

8. The Structure of a Basic C Program

A C program follows a structured format. Understanding this structure
makes it easier to read and create programs.

#include <stdio.h>

int main() {

    printf("Hello from Hadi W3B");

    return 0;
}

Breaking the Program into Parts

9. Comments in C

Comments are notes written inside source code to explain what the code
does. The compiler ignores comments during program execution.

Single-Line Comment

// This line explains the purpose of the code

Multi-Line Comment

/*
   This is a multi-line comment.
   It can contain multiple explanations.
*/

10. Practical Task: Create a Digital Identity Card

Now combine the basic concepts you have learned by creating a simple
digital identity card using C.

#include <stdio.h>

int main() {

    printf("================================\n");
    printf("          HADI W3B\n");
    printf("================================\n");

    printf("Username : Hadi W3B\n");
    printf("Level    : C Programming Beginner\n");
    printf("Mission  : Master the Fundamentals\n");

    printf("================================\n");

    return 0;
}

11. What Is a Variable?

A variable is a named location in computer memory used to store
information that may be used by a program.

A Simple Variable Example

#include <stdio.h>

int main() {

    int score = 95;

    printf("%d", score);

    return 0;
}

12. Variable Declaration and Initialization

Creating a variable and giving it an initial value are two important
steps in C programming.

Declaration

int points;

This tells the compiler that a variable named points
will be used to store an integer value.

Initialization

int points = 95;

This creates the variable and gives it an initial value at the same
time.

13. Rules for Naming Variables

Variable names make programs easier to understand, but C follows
specific rules when creating them.

Valid Variable Names

int score;
int playerLevel;
int totalPoints;
int _counter;

Invalid Variable Names

int player level;
int 2score;
int total-points;

14. What Is a Constant?

A constant is a value that is intended to remain unchanged during the
execution of a program.

Constants are useful when a value has a fixed meaning throughout a
program.

#include <stdio.h>

int main() {

    const int MAX_LEVEL = 100;

    printf("%d", MAX_LEVEL);

    return 0;
}

15. What Are Data Types?

A data type tells the compiler what kind of information a variable will
store and how that information should be handled in memory.

16. The char Data Type

The char data type is commonly used to store a single
character.

#include <stdio.h>

int main() {

    char symbol = 'H';

    printf("%c", symbol);

    return 0;
}

17. The int Data Type

The int data type is commonly used to store whole numbers
without a decimal portion.

#include <stdio.h>

int main() {

    int completedTasks = 24;

    printf("%d", completedTasks);

    return 0;
}

18. The float Data Type

The float data type is used to store numbers that contain
a decimal portion.

#include <stdio.h>

int main() {

    float temperature = 27.5f;

    printf("%.1f", temperature);

    return 0;
}

19. The double Data Type

The double data type is commonly used when more precision
is required for decimal values.

#include <stdio.h>

int main() {

    double distance = 123.456789;

    printf("%.6lf", distance);

    return 0;
}

20. Understanding Bits and Bytes

Computer memory stores information using binary digits. These binary
digits are called bits.

21. Measuring Data Type Memory with sizeof()

The sizeof() operator can be used to determine how much
memory a data type or variable occupies.

#include <stdio.h>

int main() {

    printf("char   : %zu bytes\n", sizeof(char));
    printf("int    : %zu bytes\n", sizeof(int));
    printf("float  : %zu bytes\n", sizeof(float));
    printf("double : %zu bytes\n", sizeof(double));

    return 0;
}

22. Understanding the Range of a Data Type

The number of bits available to a data type determines how many
different values it can represent.

Example: 8 Bits

If a value uses 8 bits, the total number of possible binary
combinations is:

These values can be represented from 0 to 255 when all
8 bits are used for non-negative values.

23. Unsigned Range Formula

An unsigned data type represents only zero and positive values.

Example: 8-Bit Unsigned Value

24. Signed Range Formula

A signed data type can represent both negative and positive values.

Example: 8-Bit Signed Value

25. Practical Task: Create a Data Profile

Create a program that stores different kinds of information using
different data types and displays the results.

#include <stdio.h>

int main() {

    char rank = 'A';
    int missions = 12;
    float progress = 87.5f;
    double accuracy = 98.765432;

    printf("Rank     : %c\n", rank);
    printf("Missions : %d\n", missions);
    printf("Progress : %.1f%%\n", progress);
    printf("Accuracy : %.6lf%%\n", accuracy);

    return 0;
}

26. Understanding Number Systems

Computers do not naturally process numbers in the same way humans
usually write them. Different number systems are used to represent and
process numerical information.

27. The Decimal Number System

The decimal number system is the system people use most commonly in
everyday life. It is based on ten digits.

Example: 583

28. The Binary Number System

Binary is the fundamental number system used by digital computers. It
contains only two digits: 0 and 1.

Example: Binary 1011

29. The Octal Number System

The octal number system uses eight digits, from 0 to 7.

Example: Octal 247

30. The Hexadecimal Number System

Hexadecimal is a base-16 number system. It uses numbers from 0 to 9
and letters from A to F.

Example: Hexadecimal 2A

31. Decimal to Binary Conversion

To convert a decimal number into binary, repeatedly divide the number
by 2 and record the remainders.

Example: Convert 25 to Binary

32. Binary to Decimal Conversion

To convert binary into decimal, multiply each binary digit by its
corresponding power of 2.

Example: Convert 11001 to Decimal

33. Decimal to Octal Conversion

To convert a decimal number into octal, repeatedly divide the number
by 8 and record the remainders.

Example: Convert 83 to Octal

34. Decimal to Hexadecimal Conversion

To convert a decimal number into hexadecimal, repeatedly divide the
number by 16 and record the remainders.

Example: Convert 42 to Hexadecimal

35. Understanding ASCII

ASCII stands for American Standard Code for Information Interchange.
It assigns numerical values to characters so computers can represent
text digitally.

36. ASCII Conversion Example

The character A can be converted into different number systems using
its ASCII decimal value.

C Program to Display an ASCII Value

#include <stdio.h>

int main() {

    char symbol = 'A';

    printf("Character : %c\n", symbol);
    printf("ASCII Code: %d\n", symbol);

    return 0;
}

37. The printf() Function

The printf() function is used to display formatted
information on the screen.

#include <stdio.h>

int main() {

    printf("Welcome to C Programming\n");
    printf("Created for Hadi W3B\n");

    return 0;
}

38. The scanf() Function

The scanf() function is used to receive input from the
user through the keyboard.

#include <stdio.h>

int main() {

    int age;

    printf("Enter your age: ");
    scanf("%d", &age);

    printf("Your age is: %d", age);

    return 0;
}

39. Common Format Specifiers

Format specifiers tell C how a value should be read or displayed.

40. Escape Sequences

Escape sequences are special character combinations used to control the
formatting of text displayed by a C program.

Escape Sequence Example

#include <stdio.h>

int main() {

    printf("HADI W3B\n");
    printf("C Programming\tFoundation\n");
    printf("\"Keep Learning\"");

    return 0;
}

41. Practical Task: Build a Conversion Display

Create a program that displays the same character in character,
decimal ASCII, binary and hexadecimal forms.

#include <stdio.h>

int main() {

    char symbol = 'A';

    printf("==============================\n");
    printf("       CHARACTER PROFILE\n");
    printf("==============================\n");

    printf("Character       : %c\n", symbol);
    printf("Decimal ASCII   : %d\n", symbol);
    printf("Hexadecimal     : %X\n", symbol);

    printf("==============================\n");

    return 0;
}

42. Understanding C Tokens

A C program is made up of small individual elements called tokens.
Tokens are the basic building blocks that form a complete C program.

Example

int score = 95;

43. What Are Keywords?

Keywords are reserved words that have a predefined meaning in the C
programming language.

44. What Are Identifiers?

Identifiers are names created by the programmer for variables,
functions and other program elements.

int totalScore;
float averageValue;
char grade;

In this example,
totalScore,
averageValue and
grade are identifiers.

45. What Are Constants?

A constant is a fixed value that does not change during the execution
of a program.

int maximumScore = 100;
char level = 'A';
float rating = 4.5f;

46. What Are Operators?

Operators are special symbols used to perform operations on values and
variables.

47. Arithmetic Operators

Arithmetic operators are used for mathematical calculations.

#include <stdio.h>

int main() {

    int firstValue = 20;
    int secondValue = 6;

    printf("Addition       : %d\n", firstValue + secondValue);
    printf("Subtraction    : %d\n", firstValue - secondValue);
    printf("Multiplication  : %d\n", firstValue * secondValue);
    printf("Division       : %d\n", firstValue / secondValue);
    printf("Remainder      : %d\n", firstValue % secondValue);

    return 0;
}

48. Assignment Operator

The assignment operator is used to place a value into a variable.

int points;

points = 250;

The value 250 is assigned to the variable
points.

49. Relational Operators

Relational operators compare two values. The result of a comparison is
generally either true or false.

#include <stdio.h>

int main() {

    int firstValue = 25;
    int secondValue = 15;

    printf("%d\n", firstValue > secondValue);
    printf("%d\n", firstValue == secondValue);
    printf("%d\n", firstValue != secondValue);

    return 0;
}

50. Logical Operators

Logical operators are used to combine or reverse conditions.

51. Expressions in C

An expression is a combination of values, variables and operators that
produces a result.

int total = 20 + 15;

In the expression 20 + 15, the values are combined
using an arithmetic operator to produce the result 35.

52. Operator Precedence

When an expression contains multiple operators, C follows a specific
order to determine which operation should be performed first.

Example

int result = 10 + 5 * 2;

Using Parentheses

int result = (10 + 5) * 2;

53. Type Conversion

Type conversion occurs when a value is converted from one data type
into another data type.

Automatic Conversion

#include <stdio.h>

int main() {

    int wholeNumber = 25;
    float result = wholeNumber;

    printf("%.2f", result);

    return 0;
}

Explicit Conversion

#include <stdio.h>

int main() {

    int total = 7;
    int items = 2;

    float average = (float) total / items;

    printf("%.2f", average);

    return 0;
}

54. Practical Task: Create a Score Analyzer

Create a program that stores three scores and calculates the total and
average using arithmetic operators.

#include <stdio.h>

int main() {

    int scoreOne = 78;
    int scoreTwo = 86;
    int scoreThree = 92;

    int total = scoreOne + scoreTwo + scoreThree;

    float average = (float) total / 3;

    printf("Score One   : %d\n", scoreOne);
    printf("Score Two   : %d\n", scoreTwo);
    printf("Score Three : %d\n", scoreThree);

    printf("Total       : %d\n", total);
    printf("Average     : %.2f\n", average);

    return 0;
}

55. Practical Task: Calculate a Rectangle

Create a program that calculates the area and perimeter of a rectangle.

#include <stdio.h>

int main() {

    float length = 12.5f;
    float width = 7.5f;

    float area = length * width;
    float perimeter = 2 * (length + width);

    printf("Length    : %.2f\n", length);
    printf("Width     : %.2f\n", width);
    printf("Area      : %.2f\n", area);
    printf("Perimeter : %.2f\n", perimeter);

    return 0;
}

56. Practical Task: Convert Time

Create a program that converts a total number of minutes into hours
and remaining minutes.

#include <stdio.h>

int main() {

    int totalMinutes = 185;

    int hours = totalMinutes / 60;
    int remainingMinutes = totalMinutes % 60;

    printf("Total Minutes      : %d\n", totalMinutes);
    printf("Complete Hours     : %d\n", hours);
    printf("Remaining Minutes  : %d\n", remainingMinutes);

    return 0;
}

57. Practical Task: Create a Currency Calculator

Create a simple program that calculates the total cost of multiple
items using a price and quantity.

#include <stdio.h>

int main() {

    float price = 24.50f;
    int quantity = 4;

    float totalCost = price * quantity;

    printf("Price       : $%.2f\n", price);
    printf("Quantity    : %d\n", quantity);
    printf("Total Cost  : $%.2f\n", totalCost);

    return 0;
}

58. Practical Task: Analyze a Three-Digit Number

Create a program that separates a three-digit number into its
individual digits.

#include <stdio.h>

int main() {

    int number = 482;

    int firstDigit = number / 100;
    int remaining = number % 100;

    int secondDigit = remaining / 10;
    int thirdDigit = remaining % 10;

    printf("Original Number : %d\n", number);
    printf("First Digit     : %d\n", firstDigit);
    printf("Second Digit    : %d\n", secondDigit);
    printf("Third Digit     : %d\n", thirdDigit);

    return 0;
}