Files
UoL/CM2005 Object Oriented Programming/Topic 2/2.3.13/main.cpp

99 lines
2.6 KiB
C++

#include <iostream>
#include <string>
#include <vector>
enum class OrderBookType
{
bid,
ask
};
class OrderBookEntry
{
public:
OrderBookEntry(
double price,
double amount,
std::string timestamp,
std::string product,
OrderBookType orderType);
double price;
double amount;
std::string timestamp;
std::string product;
OrderBookType orderType;
};
//constructor declaration. It needs to be placed after the class declaration
OrderBookEntry::OrderBookEntry(
double price,
double amount,
std::string timestamp,
std::string product,
OrderBookType orderType
)
: price{price}, amount{amount}, timestamp{timestamp}, product{product}, orderType{orderType}
{
}
double computeAveragePrice(std::vector<OrderBookEntry>& entries)
{
double avg = 0;
for(unsigned int i=0; i<entries.size(); ++i) //thid doesn't create a copy, ++i increments on the same variable
{
//std::cout << "The price is " << entries[i].price << std::endl;
avg += entries[i].price;
}
return avg/entries.size();
}
int main()
{
std::vector<OrderBookEntry> orders;
orders.push_back( OrderBookEntry{
10000,
0.002,
"2020/03/17 17:01:24.884492",
"BTC/USDT",
OrderBookType::bid});
orders.push_back( OrderBookEntry{
50000,
0.002,
"2020/03/17 17:01:24.884492",
"BTC/USDT",
OrderBookType::bid});
// Version 1
std::cout << "Version 1" << std::endl;
for(OrderBookEntry order : orders) //this create a copy of the members of orders and assigns it to 'order'
{
std::cout << "The price is " << order.price << std::endl;
}
std::cout << "---new line---" << std::endl;
for(OrderBookEntry &order : orders) //this doesn't crate a copy
{
std::cout << "The price is " << order.price << std::endl;
}
// Version 2
std::cout << "Version 2" << std::endl;
for(unsigned int i=0; i<orders.size(); ++i) //thid doesn't create a copy, ++i increments on the same variable
{
std::cout << "The price is " << orders[i].price << std::endl;
}
//version 3
std::cout << "Version 3" << std::endl;
for(unsigned int i=0; i<orders.size(); ++i) //thid doesn't create a copy, ++i increments on the same variable
{
std::cout << "The price is " << orders.at(i).price << std::endl;
}
std::cout << "Average price: " << computeAveragePrice(orders) << std::endl;
}