cpptest.cpp

#include <iostream>
#include <vector>
#include <string>
#include <set>
#include <map>
#include <cmath>
#include "car.cpp"

using namespace std;

const long phone_number = 9123456789;

void printPhoneNumber()
{
    cout << phone_number << endl;
}

bool isValidName(string name)
{
    return name.length() > 0;
}

// named struct
struct
{
    int myNum;
    string myString;
} myStructure, myStruct2, myStruct3; // Multiple structure variables separated with commas

struct myDataType
{
    int myNum;
    string myString;
};

struct car
{
    string brand;
    string model;
    int year;
};

enum Level
{
    LOW = 10,
    MEDIUM, // 11
    HIGH    // 12
};

void displayName(string name = "N/A")
{
    cout << name << endl;
}

int getYear()
{
    return 2024;
}

// pass by reference
void swapNumber(int &x, int &y)
{
    int z = x;
    x = y;
    y = z;
}

void modifyName(string &name)
{
    name += " chan";
}

// function overload same name with difference parameters
int plusFunc(int x, int y)
{
    return x + y;
}

double plusFunc(double x, double y)
{
    return x + y;
}

// Recursive function
int sum(int k)
{
    if (k > 0)
    {
        return k + sum(k - 1);
    }
    else
    {
        return 0;
    }
}

int main()
{

    // 8 bits = 1 bytes

    int myNum = 5;            // Integer (whole number without decimals) 2 or 4 bytes
    double myFloatNum = 5.99; // Floating point number (with decimals) 8 bytes
    float totalNum = 3.2;     // Floating point number (with decimals) 4 bytes
    char myLetter = 'D';      // Character 1 bytes
    string myText = "Hello";  // String (text)  depend on the characters size
    bool myBoolean = true;    // Boolean (true or false) 1 bytes

    // Multi variable
    int x = 5, y = 6, z = 50;
    cout << x + y + z;

    // constant
    const int myNum = 15; // myNum will always be 15
    // myNum = 16; // error: assignment of read-only variable 'myNum'
    const int minutesPerHour = 60;
    const float PI = 3.14;

    // Create integer variables
    int length = 4;
    int width = 6;
    int area;

    // Calculate the area of a rectangle
    area = length * width;

    // Print the variables
    cout << "Length is: " << length << "\n";
    cout << "Width is: " << width << "\n";
    cout << "Area of the rectangle is: " << area << "\n";

    // Command Line User Input
    // int x;
    // cout << "Type a number: ";       // Type a number and press enter
    // cin >> x;                        // Get user input from the keyboard
    // cout << "Your number is: " << x; // Display the input value

    string firstName = "Theik";
    string lastName = "\"Chan\"";
    // string fullName = firstName + " " + lastName; // // string concatenation
    string fullName = firstName.append(lastName); // string concatenation
    // string fullName = format("{}.{}", firstName, lastName);
    cout << fullName;

    // Access String
    fullName.at(0); // access with position
    fullName.at(1); // access with position

    cout << fullName[fullName.length() - 1] << endl; // print last character in full name string variable

    displayName(fullName);

    // Math operation
    cout << max(10, 5);
    cout << min(10, 5);

    cout << sqrt(8);
    cout << round(2.79);
    cout << log(2);

    // boolean operation
    int myAge = 25;
    int votingAge = 18;

    cout << (myAge >= votingAge); // returns 1 (true), meaning 25 year olds are allowed to vote!
    if (myAge >= votingAge)
    {
        cout << "Old enough to vote!";
    }
    else
    {
        cout << "Not old enough to vote.";
    }

    cout << (myAge >= votingAge) ? "Old enough to vote!" : "Not old enough to vote."; // ternary operator

    // switch statement
    int day = 4;
    switch (day)
    {
    case 1:
        cout << "Monday";
        break;
    case 2:
        cout << "Tuesday";
        break;
    case 3:
        cout << "Wednesday";
        break;
    case 4:
        cout << "Thursday";
        break;
    case 5:
        cout << "Friday";
        break;
    case 6:
        cout << "Saturday";
        break;
    case 7:
        cout << "Sunday";
        break;
    default:
        cout << "Looking forward to the Weekend";
    }

    // while loop
    int i = 0;
    while (i < 5)
    {
        cout << i << "\n";
        i++;
    }

    // do while loop execute at leat one before checking the condition
    int j = 0;
    do
    {
        cout << j << "\n";
        j++;
    } while (j < 5);

    // for loop
    for (int i = 0; i <= 50; i += 10)
    {
        if (i == 20)
        {
            continue; // skip execution
        }
        if (i == 40)
        {
            break; // exit loop
        }
        cout << i << "\n";
    }
    // msg array
    vector<string> msg{"Hello", "C++", "World", "from", "VS Code", "and the C++ extension!"}; // vector resizable array
    string message[] = {};

    string cars[3] = {"Volvo", "BMW", "Ford"}; // fixed size array

    int msgSize = sizeof(msg); // size of msg array

    // multi dimensional array
    string letters[2][4] = {
        {"A", "B", "C", "D"},
        {"E", "F", "G", "H"}};

    // insert new item
    msg.push_back("theik");

    // insert new item at the beginning
    msg.insert(
        msg.begin(),
        "chan");

    // delete last 2 items
    msg.erase(
        msg.begin(),
        msg.begin() + 2);

    // search item in array
    find(
        msg.begin(),
        msg.end(),
        "theik") != msg.end();

    // loop print msg array
    for (const auto &word : msg)
    {
        cout << word << " ";
    }
    cout << endl;

    // set
    set<string> devices = {string("iphone"), "ipad"};

    // insert new item into set
    devices.insert("ipod");

    // remove item from set
    devices.erase("ipod");

    // search item in set
    devices.find("ipod") != devices.end();

    // loop print set
    for (const auto &device : devices)
    {
        cout << device << " ";
    }
    cout << endl;

    // dictionary
    map<string, int> devices_list = {
        {"iphone", 1},
        {"ipad", 2},
        {"ipod", 3}};

    // get item from dictionary
    devices_list["iphone"];

    // update item into dictionary
    devices_list["iphone"] = 5;

    // delete item from dictionary
    devices_list.erase("iphone");

    // loop print dictionary
    for (const auto &device : devices_list)
    {
        cout << device.first << " " << device.second << endl;
    }
    cout << endl;

    // boolean
    bool is_allow = true;
    if (is_allow)
    {
    }
    else
    {
    }

    // loop
    while (is_allow)
    {
        is_allow = false;
    }

    // option condition if let
    // optional<string> name{"theik chan"};
    // if (auto result = name)
    // {
    // }

    string name = "theik chan";
    // function
    printPhoneNumber();

    if (isValidName(name))
    {
        cout << "valid name" << endl;
    }
    else
    {
        cout << "invalid name" << endl;
    }

    // Assign values to members of myStructure
    myStructure.myNum = 1;
    myStructure.myString = "Hello World!";

    // Print members of myStructure
    cout << myStructure.myNum << "\n";
    cout << myStructure.myString << "\n";

    // struct
    myDataType myVar;

    car myCar;

    myCar.brand = "Toyata";
    myCar.model = "Hilux";
    myCar.year = 2010;

    // enum
    enum Level myLevel = HIGH;
    cout << myLevel;

    // Reference
    string food = "Pizza";
    string &meal = food;  // reference
    string *ptr = &food;  // pointer
    cout << ptr << "\n";  // print pointer reference memory address
    cout << *ptr << "\n"; // print value of pointer e.g Pizza

    // modify pointer value
    *ptr = "Hamburger";

    // Output the new value of the pointer (Hamburger)
    cout << *ptr << "\n";

    // Output the new value of the food variable (Hamburger)
    cout << food << "\n";

    cout << food << endl; // Outputs Pizza
    cout << meal << endl; // Outputs Pizza

    // memory address(hexadecimal number e.g 0x) of food
    cout << &food << endl;

    int currentYear = getYear();
    cout << currentYear << endl;

    int num1 = 10;
    int num2 = 20;
    swapNumber(num1, num2); // pass by reference

    cout << num1 << num2 << endl;

    string name = "theik";
    modifyName(name);

    cout << name << endl;

    // function overload
    int myNum1 = plusFunc(8, 5);
    double myNum2 = plusFunc(4.3, 6.26);
    cout << "Int: " << myNum1 << "\n";
    cout << "Double: " << myNum2;

    // function call to recursive function
    int result = sum(10);
    cout << result;

    // Create an object of Car
    Car carObj1;
    carObj1.brand = "BMW";
    carObj1.model = "X5";
    carObj1.year = 1999;

    // Create another object of Car
    Car carObj2;
    carObj2.brand = "Ford";
    carObj2.model = "Mustang";
    carObj2.year = 1969;

    // Print attribute values
    cout << carObj1.brand << " " << carObj1.model << " " << carObj1.year << "\n";
    cout << carObj2.brand << " " << carObj2.model << " " << carObj2.year << "\n";
}