Programming in C++ – Complete Beginner’s Guide with Examples, Exercises & Downloadable PDFs

#include <iostream>
using namespace std;

int main() {
    // Integer: whole numbers
    int age = 20;
    cout << "Integer example (age): " << age << endl;

    // Floating-point: numbers with decimal
    float height = 5.9;
    double weight = 70.5;
    cout << "Float example (height): " << height << endl;
    cout << "Double example (weight): " << weight << endl;

    // Character: single letter or symbol
    char grade = 'A';
    cout << "Character example (grade): " << grade << endl;

    // Boolean: true or false
    bool isStudent = true;
    cout << "Boolean example (isStudent): " << isStudent << endl;

    // String: sequence of characters
    string name = "Ali";
    cout << "String example (name): " << name << endl;

    return 0;
}

#include <iostream>
using namespace std;

int main() {
    // Character variable
    char grade = 'A';
    char symbol = '#';
    char letter = 'Z';

    cout << "Character example 1 (grade): " << grade << endl;
    cout << "Character example 2 (symbol): " << symbol << endl;
    cout << "Character example 3 (letter): " << letter << endl;

    return 0;
}

#include <iostream>
#include <limits> // for numeric_limits
using namespace std;

int main() {
    // Find the maximum and minimum values an int can hold
    int maxValue = numeric_limits<int>::max();
    int minValue = numeric_limits<int>::min();

    cout << "Maximum value of int: " << maxValue << endl;
    cout << "Minimum value of int: " << minValue << endl;

    // Overflow: adding 1 to the maximum value
    cout << "\nAfter overflow (maxValue + 1): " << (maxValue + 1) << endl;

    // Underflow: subtracting 1 from the minimum value
    cout << "After underflow (minValue - 1): " << (minValue - 1) << endl;

    return 0;
}

#include <iostream>
using namespace std;

int main() {
    // 1. What is a variable?
    // A variable is a name that stores a value in memory. 
    // You can change the value of a variable during program execution.

    // 2. Variable declaration and initialization
    int age = 20;          // 'int' is the type, 'age' is the variable name, 20 is the initial value
    float height = 5.9;    // float stores numbers with decimals
    char grade = 'A';      // char stores a single character
    bool isStudent = true; // bool stores true or false
    string name = "Ali";   // string stores a sequence of characters

    // 3. Printing variable values
    cout << "Age: " << age << endl;
    cout << "Height: " << height << endl;
    cout << "Grade: " << grade << endl;
    cout << "Is student? " << isStudent << endl;
    cout << "Name: " << name << endl;

    // 4. Changing variable values
    age = 21;   // Value of 'age' is updated
    name = "Ahmed"; // Value of 'name' is updated

    cout << "\nAfter updating variables:" << endl;
    cout << "Age: " << age << endl;
    cout << "Name: " << name << endl;

    /* 5. Rules for declaring variables:
        - Must start with a letter or underscore (_)
        - Can contain letters, digits, and underscores
        - Cannot start with a digit
        - Cannot use C++ keywords (like int, float, return, etc.)
        - Should have meaningful names
    */

    return 0;
}

#include <iostream>
using namespace std;

int main() {
    // 1. Integer literal
    int age = 25;  
    cout << "Integer literal (age): " << age << endl;

    // 2. Long integer literal
    long population = 7800000000L; // 'L' specifies a long literal
    cout << "Long literal (population): " << population << endl;

    // 3. Floating-point literal
    float height = 5.9f;   // 'f' specifies a float literal
    double weight = 70.5;  // double literal by default
    cout << "Float literal (height): " << height << endl;
    cout << "Double literal (weight): " << weight << endl;

    // 4. Character literal
    char grade = 'A';  
    cout << "Character literal (grade): " << grade << endl;

    // 5. Boolean literal
    bool isStudent = true;  
    cout << "Boolean literal (isStudent): " << isStudent << endl;

    // 6. String literal
    string name = "Ali";  
    cout << "String literal (name): " << name << endl;

    // 7. Escape sequence literal
    cout << "This is a new line\nand this is the next line using a literal." << endl;

    return 0;
}

#include <iostream>
using namespace std;

// 1. Using #define to define a constant value
#define PI 3.14159

int main() {
    // 2. Using const to declare a constant variable
    const int DAYS_IN_WEEK = 7;

    // Trying to change a const variable will cause an error
    // DAYS_IN_WEEK = 8; // ❌ Uncommenting this line will give an error

    cout << "Value of PI using #define: " << PI << endl;
    cout << "Days in a week using const: " << DAYS_IN_WEEK << endl;

    // Example usage in calculation
    float radius = 5.0;
    float area = PI * radius * radius; // Using #define constant
    cout << "Area of circle with radius " << radius << " is: " << area << endl;

    return 0;
}

#include <iostream>
using namespace std;

// Using #define to create a constant
#define PI 3.14159
#define GREETING "Hello, World!"

int main() {
    // Using the defined constant
    float radius = 5.0;
    float area = PI * radius * radius; // Using #define constant

    cout << GREETING << endl; // Using #define string literal
    cout << "Radius: " << radius << endl;
    cout << "Area of circle: " << area << endl;

    return 0;
}

#include <iostream>
using namespace std;

int main() {
    int a = 15;
    int b = 4;

    cout << "Values: a = " << a << ", b = " << b << endl;

    // 1. Addition (+)
    cout << "a + b = " << a + b << endl;

    // 2. Subtraction (-)
    cout << "a - b = " << a - b << endl;

    // 3. Multiplication (*)
    cout << "a * b = " << a * b << endl;

    // 4. Division (/)
    cout << "a / b = " << a / b << " (integer division)" << endl;

    // 5. Modulus (%) - remainder of division
    cout << "a % b = " << a % b << endl;

    // 6. Increment (++) - increases value by 1
    a++;
    cout << "After increment, a = " << a << endl;

    // 7. Decrement (--) - decreases value by 1
    b--;
    cout << "After decrement, b = " << b << endl;

    return 0;
}

#include <iostream>
using namespace std;

int main() {
    int a = 10; // Simple assignment (=)
    int b = 5;

    cout << "Initial values: a = " << a << ", b = " << b << endl;

    // 1. Addition assignment (+=)
    a += b; // equivalent to a = a + b
    cout << "After a += b, a = " << a << endl;

    // 2. Subtraction assignment (-=)
    a -= b; // equivalent to a = a - b
    cout << "After a -= b, a = " << a << endl;

    // 3. Multiplication assignment (*=)
    a *= b; // equivalent to a = a * b
    cout << "After a *= b, a = " << a << endl;

    // 4. Division assignment (/=)
    a /= b; // equivalent to a = a / b
    cout << "After a /= b, a = " << a << endl;

    // 5. Modulus assignment (%=)
    a %= b; // equivalent to a = a % b
    cout << "After a %= b, a = " << a << endl;

    return 0;
}

#include <iostream>
using namespace std;

int main() {
    int a = 5;
    int b = 5;

    cout << "Initial values: a = " << a << ", b = " << b << endl;

    // 1. Prefix increment: ++a
    // The value is incremented first, then used
    int prefixResult = ++a;
    cout << "After prefix increment (++a): a = " << a << ", result = " << prefixResult << endl;

    // 2. Postfix increment: b++
    // The value is used first, then incremented
    int postfixResult = b++;
    cout << "After postfix increment (b++): b = " << b << ", result = " << postfixResult << endl;

    return 0;
}

#include <iostream>
using namespace std;

int main() {
    int a = 10, b = 5, c = 2;

    // Without parentheses
    int result1 = a + b * c; 
    // Multiplication (*) has higher precedence than addition (+)
    cout << "Result without parentheses (a + b * c): " << result1 << endl;

    // With parentheses
    int result2 = (a + b) * c; 
    // Parentheses change the order of evaluation
    cout << "Result with parentheses ((a + b) * c): " << result2 << endl;

    // Combining multiple operators
    int result3 = a + b - c * 2 / 2;
    // Operator precedence: *, / first, then +, -
    cout << "Result of a + b - c * 2 / 2: " << result3 << endl;

    return 0;
}