C++ Refresher by Christopher Pelech
The Following are some super helpful classes that should give you an idea about some basic c++ structure.
This is the example of a main function. This is where the program starts. My background is in video game development so I tend to move all my code over to classes Click here to download the source
main.cpp
#include "GameManager.h"
int main() {
GameManager _GameManager;
_GameManager.Update();
}
This is a example of a Class Header. Within it you can find examples of a static variables, enums, and function definitions
GameManager.h
#pragma once
#include iostream
#include stdio.h
#include string
#include sstream
#include cctype
#include "WeaponManager.h"
#include "MathProblemManager.h"
using namespace std;
class GameManager
{
public:
//=========== public Vars =================
static bool GameActive;
static string userName;
static string answer;
WeaponManager _WeaponManager;
MathProblemManager _MathProblemManager;
//=========== Enums ====================
enum GameState{ GET_USER_NAME, WEAPON_MANAGER, MATH_PROBLEMS, BIT_SHIFTING, QUITTING};
static GameState _currentGameState;
//=========== public Functions =================
GameManager(void);
~GameManager(void);
// ==== Useful Functions ===================
static void printScreen(string val);
static void ClearScreen();
static void Pause();
static int GetIntFromInput();
//====== Main game loop ===========
void Update();
// ===== Change current state ======
static void ChangeState();
//====== Our State functions ====================
void GetUserName();
void UpdateWeaponManager();
void UpdateMathProblemManager();
void UpdateBitShiftManager();
void QuitGame();
};
#pragma endregion
This is the example of class definitions, as well as how to instantiate a public static var. In addition a good example of a state system is shown, as well as an basic I/O example.
GameManager.cpp
#include "GameManager.h"
//==================================== Static Vars =================================
GameManager::GameState GameManager::_currentGameState = GameManager::GameState::GET_USER_NAME;
bool GameManager::GameActive = true;
string GameManager::userName = "";
string GameManager::answer = "";
//====================== Constructor/Destructor ============================
GameManager::GameManager(void){
}
GameManager::~GameManager(void){
}
//====================== Useful Functions ============================
void GameManager::printScreen(string val){ cout << val <<"\n\n"; }
void GameManager::ClearScreen(){ std::system("CLS"); }
void GameManager::Pause(){ printScreen("Press Any Key to continue..."); getline(cin, answer); }
int GameManager::GetIntFromInput(){
int val;
bool success = false;
bool failed = false;
while(!success){
if(failed) printScreen("\n(I'm sorry I didnt understand that, please Enter a number)");
else printScreen("(Please input a Decimal Number: )");
string input = ""; getline(cin, input);
bool has_only_digits = true;
for (size_t n = 0; n < input.length(); n++) {
bool isNegativeSymbol = (input[n] == '-' && n == 0);
if (!isdigit(input[n]) && !isNegativeSymbol){
has_only_digits = false;
break;
}
}
if(has_only_digits) { stringstream(input) >> val; success = true; }
else { failed = true; }
}
return val;
}
//====================== Main Game Loop ============================
void GameManager::Update(){
while(GameActive){
ClearScreen();
if(_currentGameState == GameManager::GameState::GET_USER_NAME) GetUserName();
else if(_currentGameState == GameManager::GameState::WEAPON_MANAGER) _WeaponManager.Update();
else if(_currentGameState == GameManager::GameState::MATH_PROBLEMS) _MathProblemManager.Update();
else if(_currentGameState == GameManager::GameState::BIT_SHIFTING) UpdateBitShiftManager();
else if(_currentGameState == GameManager::GameState::QUITTING) QuitGame();
}
}
void GameManager::ChangeState(){
bool answeredCorrectly = false;
bool failed = false;
while(!answeredCorrectly){
ClearScreen();
if(failed){ failed = false; printScreen("I'm sorry I didnt catch that " + userName + ", please try again \n\n 0) Enter User Name \n 1) Weapon Manager \n 2) Math Problems \n 3) Bit Shifting \n Q) Quit");}
else {printScreen("Hello " + userName + ", Please Select a Option to continue: \n\n 0) Enter User Name \n 1) Weapon Manager \n 2) Math Problems \n 3) Bit Shifting \n Q) Quit");}
string val = "";
getline(cin,val);
if(val == "0") _currentGameState = GameState::GET_USER_NAME;
else if(val == "1") _currentGameState = GameState::WEAPON_MANAGER;
else if(val == "2") _currentGameState = GameState::MATH_PROBLEMS;
else if(val == "3") _currentGameState = GameState::BIT_SHIFTING;
else if(val == "Q" || val == "q") _currentGameState = GameState::QUITTING;
else{ failed = true; continue; }
answeredCorrectly = true;
}
}
//====================== Update the current state ============================
void GameManager::GetUserName(){
printScreen("Hello, my name is Thursday. What would you like me to call you?"); getline(cin,userName);
ChangeState();
}
void GameManager::QuitGame(){
printScreen("Are you sure you want to quit? (Press 0 to exit, anything else to cancel)");
getline(cin, answer);
if(answer == "0") {GameActive = false; printScreen(""); }
else{ChangeState();}
}
void GameManager::UpdateWeaponManager(){ ChangeState(); }
void GameManager::UpdateMathProblemManager(){ ChangeState(); }
void GameManager::UpdateBitShiftManager(){ ChangeState(); }
Finally I'll show you a example of structs and how useful the vector class is by doing a basic weapon manager system.
WeaponManager.h
#pragma once
#include iostream>
#include stdio.h>
#include string>
#include vector>
using namespace std;
class WeaponManager
{
public:
// ========== Structs =============
struct WeaponItem{
string WeaponName;
int WeaponDamage;
int AmmoLeft;
int MaxAmmo;
WeaponItem() : WeaponName("Null"), WeaponDamage(0), AmmoLeft(0), MaxAmmo(0) {}
WeaponItem(string name, int damage, int ammo) : WeaponName(name), WeaponDamage(damage), AmmoLeft(ammo), MaxAmmo(ammo) {}
void FireWeapon() {
if (AmmoLeft > 0) { AmmoLeft -= 1; cout << "\nFired the Weapon: " << WeaponName << ", did " << WeaponDamage << " damage, " << AmmoLeft << " ammo remaining"; }
else{ cout << "\The Weapon: " << WeaponName << ", Does not have enough ammo to fire."; }
}
void ReloadWeapon() { AmmoLeft = MaxAmmo; cout << "You have reloaded the weapon " << WeaponName; }
void PrintWeapon() { cout << "\n Weapon Name: " << WeaponName << ", Damage: " << WeaponDamage << ", Current Ammo: " << AmmoLeft << ", Max Ammo: " + MaxAmmo; }
};
// ======= Enums =========
enum WeaponManagerState { Idle, AddingWeapon, RemovingWeapon, PrintingWeaponList, ChangingWeapon, FiringCurrentWeapon, Reloading, Exit};
// ======== Vars ===========
static int CurrentWeaponItem;
static std::vector[WeaponItem] Inventory;
static WeaponManagerState currentState;
// ======= Constructors =========
WeaponManager(void);
~WeaponManager(void);
// ======= Functions =============
void Update();
void ChangeWeaponState();
void AddWeapon();
void RemoveWeapon();
void PrintWeaponList();
void ChangeCurrentWeapon();
void FireCurrentWeapon();
void DoReload();
void DoExit();
void backToIdle();
};
Just like before, here is the class definitions
WeaponManager.cpp
#include "GameManager.h"
#pragma region ==================== Static Vars ====================
WeaponManager::WeaponManagerState WeaponManager::currentState = WeaponManager::WeaponManagerState::Idle;
std::vector[WeaponManager::WeaponItem] WeaponManager::Inventory;
int WeaponManager::CurrentWeaponItem = -1;
#pragma endregion
#pragma region ==================== Constructors ====================
WeaponManager::WeaponManager(void) {}
WeaponManager::~WeaponManager(void){}
#pragma endregion
#pragma region ==================== Generic Functions ====================
void WeaponManager::DoExit() { GameManager::Pause(); GameManager::ChangeState(); }
void WeaponManager::backToIdle() { cout << "\n"; GameManager::Pause(); currentState = WeaponManagerState::Idle; }
#pragma endregion
#pragma region ==================== Main Loop ====================
void WeaponManager::Update() {
std::system("CLS");
if (currentState == WeaponManagerState::Idle) { ChangeWeaponState(); }
else if (currentState == WeaponManagerState::AddingWeapon) { AddWeapon(); }
else if (currentState == WeaponManagerState::ChangingWeapon) { ChangeCurrentWeapon(); }
else if (currentState == WeaponManagerState::FiringCurrentWeapon) { FireCurrentWeapon(); }
else if (currentState == WeaponManagerState::PrintingWeaponList) { PrintWeaponList(); }
else if (currentState == WeaponManagerState::RemovingWeapon) { RemoveWeapon(); }
else if (currentState == WeaponManagerState::Reloading) { DoReload(); }
else if (currentState == WeaponManagerState::Exit) {}
}
#pragma endregion
#pragma region ==================== Change State ====================
void WeaponManager::ChangeWeaponState() {
bool answeredCorrectly = false;
bool failed = false;
while (!answeredCorrectly) {
std::system("CLS");
string options = "\n\n1) AddingWeapon \n2) ChangingWeapon \n3) FiringCurrentWeapon \n4) PrintingWeaponList \n5) RemovingWeapon \n6) Reloading \nQ) Exit \n\n";
if (failed) { failed = false; cout << "I'm sorry I didnt catch that , please try again " << options; }
else { cout << "Please Select a Option to continue: " << options; }
string val = "";
getline(cin, val);
if (val == "1") currentState = WeaponManagerState::AddingWeapon;
else if (val == "2") currentState = WeaponManagerState::ChangingWeapon;
else if (val == "3") currentState = WeaponManagerState::FiringCurrentWeapon;
else if (val == "4") currentState = WeaponManagerState::PrintingWeaponList;
else if (val == "5")currentState = WeaponManagerState::RemovingWeapon;
else if (val == "6")currentState = WeaponManagerState::Reloading;
else if (val == "Q" || val == "q") currentState = WeaponManagerState::Exit;
else { failed = true; continue; }
answeredCorrectly = true;
}
}
#pragma endregion
#pragma region ==================== Add Weapon ====================
void WeaponManager::AddWeapon() {
string _weaponName = "";
cout << "\nPlease Enter a weapon name: \n\n";
getline(cin, _weaponName);
int damage = 0, ammo = 1;
cout << "\nPlease Enter a weapon Damage: ";
damage = GameManager::GetIntFromInput();
cout << "\nPlease Enter a Max Ammo: ";
ammo = GameManager::GetIntFromInput();
WeaponManager::WeaponItem tempItem(_weaponName, damage, ammo);
Inventory.push_back(tempItem);
if (CurrentWeaponItem == -1) CurrentWeaponItem = 0;
cout << "\n\nAdded the weapon: " << tempItem.WeaponName << ", to inventory \n";
backToIdle();
}
#pragma endregion
#pragma region ==================== Change Current Weapon ====================
void WeaponManager::ChangeCurrentWeapon() {
if (Inventory.size() > 0) {
bool success = false;
bool failed = false;
while (!success) {
std::system("CLS");
if (failed) cout << "\nI'm sorry I didnt catch that... What Index would you like to remove the in the list? \n";
else cout << "\nWhat Index would you like to remove the in the list? \n";
for (int i = 0; i < Inventory.size(); i++) { cout << "\n " << i << ") " << Inventory[i].WeaponName; }
cout << "\n\n";
int answer = GameManager::GetIntFromInput();
if (answer > 0 && answer < Inventory.size()) {
CurrentWeaponItem = answer;
cout << "\nThe current selected weapon is: " << Inventory[CurrentWeaponItem].WeaponName << "\n";
success = true;
}
else {
failed = true;
}
}
}
else {
cout << "\nI'm sorry the current inventory is empty\n";
}
backToIdle();
}
#pragma endregion
#pragma region ==================== Fire Current Weapon ====================
void WeaponManager::FireCurrentWeapon() {
if (CurrentWeaponItem == -1) {
cout << "\nNo weapon is currently selected, please select a weapon\n";
}else {
bool firing = true;
while (firing) {
Inventory[CurrentWeaponItem].FireWeapon();
cout << "\n\nWould you like to Fire Again? (0 = No, anything else for yes)\n";
string answer = "";
getline(cin, answer);
if (answer == "0") { firing = false; }
else{ std::system("CLS"); }
}
}
backToIdle();
}
#pragma endregion
#pragma region ==================== Print Weapon List ====================
void WeaponManager::PrintWeaponList() {
cout << "\nPrinting the Inventory: \n";
for (int i = 0; i < Inventory.size(); i++){ Inventory[i].PrintWeapon(); }
backToIdle();
}
#pragma endregion
#pragma region ==================== Remove Weapon ====================
void WeaponManager::RemoveWeapon() {
if (Inventory.size() > 0) {
bool success = false;
bool failed = false;
while (!success) {
std::system("CLS");
if(failed) cout << "\nI'm sorry I didnt catch that... What Index would you like to remove the in the list? \n";
else cout << "\nWhat Index would you like to remove the in the list? \n";
for (int i = 0; i < Inventory.size(); i++) { cout << "\n " << i << ") " << Inventory[i].WeaponName; }
cout << "\n";
int answer = GameManager::GetIntFromInput();
if (answer >= 0 && answer < Inventory.size()) {
Inventory.erase(Inventory.begin() + answer);
if (Inventory.size() == 0) { CurrentWeaponItem = -1; }
else if (CurrentWeaponItem >= Inventory.size()) { CurrentWeaponItem = Inventory.size() - 1; }
else if (CurrentWeaponItem >= answer) { CurrentWeaponItem -= 1; }
}
else {
failed = true;
}
}
}
else { cout << "\nI'm sorry the current inventory is empty";}
backToIdle();
}
#pragma endregion
#pragma region ==================== Reload Weapon ====================
void WeaponManager::DoReload() {
if (CurrentWeaponItem == -1) {
cout << "\nNo weapon is currently selected, please select a weapon";
}
else {
Inventory[CurrentWeaponItem].ReloadWeapon();
}
backToIdle();
}
#pragma endregion
Hoped this refresher helped! Be sure to leave feedback