IronCodeMan

Concepts for C++

C++ is a powerful, versatile programming language that extends the capabilities of C with features like object-oriented programming, templates, and standard libraries. Developed by Bjarne Stroustrup in the 1980s, C++ is widely used in a variety of domains, including systems programming, game development, and high-performance applications. It offers both low-level control over hardware resources and high-level abstractions for building complex software systems. With its support for features like classes, inheritance, and polymorphism, C++ facilitates the creation of modular, reusable code. Despite its complexity and steep learning curve, C++ remains a popular choice for developers seeking performance, flexibility, and control in their projects.

Print Text

#include <iostream>
using namespace std;

int main() {
  cout << "Hello World!";
  return 0;
}

Comments

// one line comment

/*
multi 
line 
comment
*/

Variables

int carCount = 2;
string name = "Joe";
bool isPurple = true;

Data Types

int carCount = 2;
unsigned int age = 15;
signed short int seaLevel = -10000;
long long int usBudget = 11000000000;
unsigned long long int lightSpeed = 11799312874;
float myGPA = 3.45f;
double piValue = 3.14159265;
char lastLetter = 'Z';
bool isMale = true;

#include <iostream>
using namespace std;
string myName = "Joe";

Math Op

int carCount = 6;
int truckCount = 3;

int total = carCount + truckCount;
cout << total << endl;

int subtract = carCount - truckCount;
cout << subtract << endl;

int multiple = carCount * truckCount;
cout << multiple << endl;

int divisible = carCount / truckCount;
cout << divisible << endl;

// performs division and gets remainder which is 0
int modulo = carCount % truckCount;
cout << modulo << endl;

Math Functions

float power = pow(3.0, 6.0);
cout << power << endl;

float root = sqrt(16.0);
cout << root << endl;

float floorVal = floor(3.14);
cout << floorVal << endl;

float ceilVal = ceil(4.3);
cout << ceilVal << endl;

float roundVal = round(3.4);
cout << roundVal << endl;

// random number from 0 to 100
random_device rd;
mt19937 gen(rd());
uniform_int_distribution<> dis(0, 100);
int ranNum = dis(gen);
cout << ranNum << endl;

If/Else

int carCount = 6;

if (carCount > 3) {
  cout << "More than three cars";
} else if (carCount == 3) {
  cout << "Equal to three cars";
} else {
  cout << "Less than three cars";
}

Ternary

int carCount = 3;

string result = (carCount > 2) ? "Yes" : "No";
cout << result;

Switch

int carCount = 3;

switch (carCount) {
  case 1:
    cout << "One car";
    break;
  case 2: 
    cout << "Two cars";
    break;
  case 3: 
    cout << "Three cars";
    break;
  default: 
    cout << "More than three";
}

Functions

#include <iostream>

int handleCars(int cars, int wheels) {
  int total = cars * wheels;
  return total;
}
  
int result = handleCars(3, 4);
std::cout << result;

Interpolation

#include <iostream>

// require c++ 20 to use
#include <format>
using namespace std;

string name = "Joe";
string car = "Mazda";
string result =
  format("{} drives a {}", name, car);
cout << result << endl;

Type Casting

#include <iostream>
#include <math.h>
using namespace std;

string squareA(int length) {
  double result = (double)(pow(length, 2));
  return to_string(result);
}

string squareL = "4";
int convertedVal =  stoi(squareL);
string area = squareA(convertedVal);
cout << area << endl;

Date and Time

#include <iostream>
#include <ctime>
using namespace std;

// set tieme in seconds since 1970
time_t secondsTime = time(nullptr);
tm *localTime = localtime(&secondsTime);

// current numeric year
int year = 1900 + localTime->tm_year;

// current numeric month
int month = 1 + localTime->tm_mon;

// current numeric day
int day = localTime->tm_mday;

// formatted date
string fullDate = to_string(month) + 
                  "/" +
                  to_string(day)+
                  "/" +
                  to_string(year);

cout << secondsTime << endl;
cout << year << endl;
cout << fullDate << endl;

Classes

#include <iostream>
#include <string>
#include <vector>
using namespace std;

class Cars {
  protected:
    vector<string> carList;
  public: 
    void addCar(string car) {
      carList.push_back(car);
    }
    void removeFirst() {
      carList.erase(carList.begin());
    }
    string getFirstVal() {
      if (carList.size() > 0) {
        return carList[0];
      }
      return "";
    }
};

Cars newList;
newList.addCar("Honda");
newList.addCar("Mazda");
newList.addCar("Toyota");
newList.removeFirst();
string firstCar = newList.getFirstVal();
cout << firstCar << endl;

Inheritance

#include <iostream>
using namespace std;

class User {
  protected:
    string username;
    string password;
  public:
    void setUser(string x, string y) {
      username = x;
      password = y;
    }
};

class Admin: public User {
  protected: 
    string id;
  public:
    void setAdmin(string x) {
      id = x;
    }
    string getUsername() {
      return username;
    }
    string getAdminID() {
      return id;
    }
};

Admin newAdmin;
newAdmin.setUser("alpha0", "pw1");
newAdmin.setAdmin("1FE");
cout << newAdmin.getUsername() << "\n";
cout << newAdmin.getAdminID() << "\n";

Method Overload

#include <iostream>
using namespace std;

class UserForm {
  public:
    string formA = "alpha";
    string formB = "beta";
    string formC = "gamma";
    string formD = "epsilon";
    
    string getForm(int age) {
      if (age > 65) {
        return formA;
      }
      return formB ;
    }

    string getForm(string formId) {
        if (formId == "gamma") {
            return formD;
        }
        return formA;
    }

    string getForm(
      bool isMilitary,
      bool isNasa
    ) {
      if (isMilitary || isNasa) {
        return formD;
      }
      return formA;
    }
};

UserForm form;
int myAge = 67;
string myId = "1FE";
bool veteran = false;
bool nasa = true;

string form1 = form.getForm(myAge);
string form2 = form.getForm(myId);
string form3 = form.getForm(veteran, nasa);
    
cout << form1 << endl;
cout << form2 << endl;
cout << form3 << endl;

Abstract Class

#include <iostream>
using namespace std;

class Animation {
  public:
    // optional to implement
    virtual void walk(){};
    
    // mandatory to implement
    virtual void run() = 0;
    virtual void idle() = 0;
};

class Human: public Animation {
  public: 
    void walk() {
      cout << "Human walks" << endl;
    }
    void run() {
      cout << "Human runs" << endl;
    }
    void idle() {
      cout << "Human idles" << endl;   
    }
};

class Zombie: public Animation {
  public:
    void run() {
      cout << "Zombie runs" << endl;
    }
    void idle() {
      cout << "Zombie idles" << endl;
    }
};

Human player;
player.walk();
    
Zombie boss1;
boss1.run();

Static Class

#include <iostream>
#include <math.h>
using namespace std;

// Not used in classes
// used in methods and variables only
class Helper {
  public:
    static double CircleA(int radius) {
      double power = pow(radius, 2);
      return (double)(3.14 * power);
    }

    static double SquareA(int length) {
      return (double)(pow(length, 2));
    }
};

double circle = Helper::CircleA(3);
cout << circle << endl;
      
double square = Helper::SquareA(4);
cout << square << endl;

Arrays/Lists

#include <iostream>
#include <string>
#include <vector>
using namespace std;

vector<string> names = {"Joe", "Alex", "Bob"};

names[1] = "Tom";
string name = names[1];
int numItems = names.size();
cout << name << endl;
cout << numItems << endl;

Array Methods

#include <iostream>
#include <vector>
using namespace std;

vector<string> cars = {"Honda", "Mazda", "Toyota"};
  
// 3 elements in vector
cout << cars.size() << endl;

// Mazda is at index 1
cout << cars.at(1) << endl;

// 1st element is Honda
cout << cars.front() << endl;

// last element is Toyota
cout << cars.back() << endl;

// replaces entire vector with two Fords
cars.assign(2, "Ford");
cout << cars[0] << endl;
cout << cars[1] << endl;

// add Tesla at the end of vector
cars.push_back("Tesla"); 
cout << cars.back() << endl;

// removes last element Tesla
cars.pop_back();
cout << cars.back() << endl;

// inserts Honda at front of vector
cars.insert(0, "Honda");
cout << cars.front() << endl;

Concatenation

#include <iostream>
#include <vector>
using namespace std;

vector<string> carListKr =
  {"Kia", "Hyundai", "Daewoo"};

vector<string> carListJp =
  {"Honda", "Mazda", "Toyota"};

vector<string> combined;

combined.insert(
  combined.end(),
  carListKr.begin(),
  carListKr.end()
);

combined.insert(
  combined.end(),
  carListJp.begin(),
  carListJp.end()
);

cout << combined[1] << endl;
cout << combined[4] << endl;

Sort Method

#include <iostream>
#include <vector>
#include <bits/stdc++.h>

using namespace std;

vector<int> ages = {5, 3, 1, 6, 7, 4, 19};

sort (ages.begin(), ages.end());
for (int i = 0; i < ages.size(); i++) {
  cout << ages[i] << endl;
}

Objects

#include <iostream>
#include <vector>
using namespace std;

class User {
  public:
    string First;
    string Last;
    int Age;
    bool Retired;
    vector<string> CarBrands;

    void setValues(
      string first,
      string last,
      int age,
      bool retired,
      vector<string> carbrands
    ){
      First = first;
      Last = last;
      Age = age;
      Retired = retired;
      CarBrands = carbrands;
    }

    string fullName() {
      return First + " " + Last;
    }
};

User user;
user.setValues(
  "Joe",
  "Doe",
  23,
  false,
  {"Mazda", "Toyota"}
);

string fullName = user.fullName();

cout << user.First << endl;
cout << user.CarBrands[1] << endl;
cout << fullName << endl;

Maps (Key/Value)

#include <iostream>
#include <map>
using namespace std;

map<string, string> carMap;
carMap["Joe"] = "Toyota";
carMap["Bob"] = "Mazda";
carMap["Tom"] = "Ford";
cout << carMap["Tom"] << endl;
  
carMap.erase("Tom");
cout << carMap.size() << endl;

Sets

#include <iostream>
#include <set>
using namespace std;

set<string> cars;
cars.insert("Mazda");
cars.insert("Toyota");
cars.insert("Honda");

bool result1 = 
  cars.find("Honda") == cars.end() ?
  false: true;
cout << result1 << endl;

cars.erase("Honda");

bool result2 = 
  cars.find("Honda") == cars.end() ?
  false: true;
cout << result2 << endl;

Stack

#include <iostream>
#include <stack>
using namespace std;

stack<string> cars;
cars.push("Mazda");
cars.push("Toyota");
cars.push("Honda");
    
cout << cars.top() << endl;;
    
cars.pop();
cout << cars.top() << endl;

Queues

#include <iostream>
#include <queue>
using namespace std;

queue<string> cars;
cars.push("Mazda");
cars.push("Toyota");
cars.push("Honda");

cout << cars.front() << endl;

cars.pop();
cout << cars.front() << endl;

Linked List

#include <iostream>
using namespace std;

struct Node {
  string value;
  struct Node *next;
};

struct Node* newNode = NULL;

class LinkedList {
  public:
    struct Node *head = NULL;
    
    void addValue(string val) {
      newNode = (struct Node*)
        malloc(sizeof(struct Node));
      newNode->value = val;

      if(head == NULL) {
          head = newNode;
      } else {
        struct Node *current = head;
        while(current->next != NULL) {
          current = current->next;
        }
        current->next = newNode;
      }
    }

    string returnHead() {
      return head->value;
    }

    void traverse() {
      struct Node *current = head;
      while(current != NULL) {
        cout << current->value << endl;
        current = current->next;
      }
    }
};

LinkedList carList;
carList.addValue("Mazda");
carList.addValue("Toyota");
carList.addValue("Honda");

cout << carList.returnHead() << endl;
carList.traverse();

Graphs

#include <iostream>
#include <queue>
#include <stack>
#include <map>
#include <vector>
using namespace std;

class Graph {
  public:
    map<string, vector<string>> graphMap;

    void addNode(string val) {
      graphMap[val] = {};
    }

    void addVertices(string node1, string node2) {
      if(graphMap.find(node1) == graphMap.end()) {
        graphMap[node1] = {};
      }
      if(graphMap.find(node2) == graphMap.end()) {
        graphMap[node2] = {};
      }

      graphMap[node1].push_back(node2);
      graphMap[node2].push_back(node1);
    }

    void breadthTraverse (string start) {
      queue<string> newQueue;
      newQueue.push(start);
      
      map<string, bool> visited;
      visited[start] = true;

      while(newQueue.size() > 0) {
        string val = newQueue.front();
        cout << val << endl;
        newQueue.pop();
        vector<string> tempArr = graphMap[val];

        for (int i = 0; i < tempArr.size(); i++) {
          if (!visited[tempArr[i]]) {
            newQueue.push(tempArr[i]);
            visited[tempArr[i]] = true;
          }
        }
      }
    }

    void depthTraverse (string start) {
      stack<string> newStack;
      newStack.push(start);

      map<string, bool> visited;
      visited[start] = true;

      while(newStack.size() > 0) {
        string val = newStack.top();
        cout << val << endl;
        newStack.pop();
        vector<string> tempArr = graphMap[val];

        for (int i = 0; i < tempArr.size(); i++) {
          if (!visited[tempArr[i]]) {
            newStack.push(tempArr[i]);
            visited[tempArr[i]] = true;
          }
        }
      }
    }
};

int main() {
  Graph newGraph;
  newGraph.addNode("a");
  newGraph.addVertices("a", "b");
  newGraph.addVertices("a", "c");
  newGraph.addVertices("b", "d");
  newGraph.addVertices("b", "e");
  newGraph.addVertices("d", "f");
  newGraph.addVertices("d", "g");
  newGraph.addVertices("d", "h");
  newGraph.addVertices("e", "i");
  newGraph.addVertices("e", "j");
  newGraph.breadthTraverse("a");
  newGraph.depthTraverse("a");
  return 0;
}

For Loops

#include <iostream>
#include <vector>
using namespace std;

vector<string> names = {"Joe", "Alex", "Bob"};
  
for (int i = 0; i < names.size(); i++) {
  cout << names[i] << endl;
}

While Loops

#include <iostream>
#include <queue>
using namespace std;

queue<string> carList;
carList.push("Mazda");
carList.push("Toyota");
carList.push("Honda");
  
while(carList.size() > 0) {
  cout << carList.front() << endl;
  carList.pop();
}

cout << carList.size() << endl;

Loop Breaks

#include <iostream>
#include <vector>
using namespace std;

vector<string> cars = {"Toyota", "Honda", "Mazda"};
  
for (int i = 0; i < cars.size(); i++) {
  if (cars[i] == "Honda") {
    cout << "Found at index " << i << endl;
    break;
  }
  cout << "Visited index " << i << endl;
}

Recursion

#include <iostream>
#include <queue>
using namespace std;

int getSum (queue<int> arr) {
  if (arr.size() == 0) {
    return 0;
  }
  int firstVal = arr.front();
  arr.pop();
  return firstVal + getSum(arr);
}

queue<int> testArr;
testArr.push(1);
testArr.push(2);
testArr.push(3);
testArr.push(5);

int sum = getSum(testArr);
cout << sum << endl;

Regex Words

#include <iostream>
#include <regex> 
#include <bits/stdc++.h>
using namespace std;

string phrase = "I am legend";
regex regexp("[a-za-zA-Z_]*");
smatch result; 
    
regex_search(phrase, result, regexp);
cout << result.str(0) << endl;

Regex Numbers

#include <iostream>
#include <regex> 
#include <bits/stdc++.h>
using namespace std;

string phrase = "I am 23";
regex regexp("[0-9_]+");
smatch result; 
    
regex_search(phrase, result, regexp);
cout << result.str(0) << endl;

Regex Test

#include <iostream>
#include <regex> 
#include <bits/stdc++.h>
using namespace std;
    
string name = "Bob Lee";
regex regexp ("Lee");
smatch m; 
    
bool result = regex_search(name, m, regexp);
cout << result << endl;

Regex Characters

#include <iostream>
#include <regex> 
#include <bits/stdc++.h>
using namespace std;

string phrase = "##I am legend##";
regex pattern ("#+[a-zA-Z]+");
smatch result; 

regex_search(phrase, result, pattern);
cout << result.str(0) << endl;

IronCodeMan

Basics

Data Structure

Iterables

Classes

Regex

Concepts for C++

Print Text

Comments

Variables

Data Types

Math Op

Math Functions

If/Else

Ternary

Switch

Functions

Interpolation

Type Casting

Date and Time

Classes

Inheritance

Method Overload

Abstract Class

Static Class

Arrays/Lists

Array Methods

Concatenation

Sort Method

Objects

Maps (Key/Value)

Sets

Stack

Queues

Linked List

Graphs

For Loops

While Loops

Loop Breaks

Recursion

Regex Words

Regex Numbers

Regex Test

Regex Characters