How would I change an array to a vector? - c++

Question

so i have this code which is a checkbook program and i have to use the STL and make it do the same thing so the only thing i can think of to change is the array in it to a vector. If you think i can do more let me know, i'm a beginner level programmer and c++ is one of my weak languages.
template <class DataType>
class Checkbook
{
public:
Checkbook( );
Checkbook( float iBalance );
void setBalance( float amnt );
bool writeCheck( const DataType & amount );
void deposit( float amount );
float getBalance( ) const;
DataType getLastCheck( ) const;
float getLastDeposit( ) const;
private:
float balance;
DataType lastCheck;
float lastDeposit;
};
template <class DataType>
bool operator > (DataType tempcheck, float z)
{
if(tempcheck.amount > z)
return true;
return false;
}
template <class DataType>
float operator - (float z, DataType tempcheck)
{
z = z - tempcheck.amount;
return z;
}
#include<iostream>
using namespace std;
template <class DataType>
Checkbook<DataType>::Checkbook( )
{}
template <class DataType>
Checkbook<DataType>::Checkbook( float initBalance )
{
balance = initBalance;
}
template <class DataType>
void Checkbook<DataType>::setBalance( float amount )
{
balance = amount;
}
template <class DataType>
bool Checkbook<DataType>::writeCheck( const DataType & amount )
{
if ( amount > balance )
return false;
balance = balance - amount;
cout<<"\n\nbalance = "<<balance<<endl<<endl;
lastCheck = amount;
return true;
}
template <class DataType>
void Checkbook<DataType>::deposit( float amount )
{
balance += amount;
lastDeposit = amount;
}
template <class DataType>
float Checkbook<DataType>::getBalance( ) const
{
return balance;
}
template <class DataType>
DataType Checkbook<DataType>::getLastCheck( ) const
{
return lastCheck;
}
template <class DataType>
float Checkbook<DataType>::getLastDeposit( ) const
{
return lastDeposit;
}
#include <iostream>
#include <iomanip>
#include <ctime>
#include <string>
#include <sstream>
using namespace std;
struct Check
{
static string Name;
static string account;
int check;
string checkDate;
float amount;
string comment;
string receipent;
};
string Check::Name = "";
string Check::account = "";
int main( )
{
struct Check ck[100];
float balance;
float Deposit=0.0;
float WriteCheck=0.0;
time_t now = time(0);
tm *ltm = localtime(&now);
string CurrentDate;
stringstream mon, day, year;
int temp;
temp = 1 + ltm->tm_mon;
mon << temp;
temp = ltm->tm_mday;
day << temp;
temp = 1900 + ltm->tm_year;
year << temp;
CurrentDate = mon.str() + "/" + day.str() + "/" + year.str();
cout<<"\nEnter name of Account Holder : ";
getline(cin,Check::Name);
cout<<"\nEnter Account No : ";
getline(cin,Check::account);
cout <<"\nEnter your initial balance: ";
cin >> balance;
Check tempCk;
Checkbook<Check> cbook( balance );
int i=0;
int j;
int choice=0;
do
{
cout<<endl<<"1- Writing checks";
cout<<endl<<"2- Show last checks";
cout<<endl<<"3- Deposit";
cout<<endl<<"4- Show Balance";
cout<<endl<<"5- Quit";
cout<<"\n\nEnter your choice : ";
cin>>choice;
switch(choice)
{
case 1:
cout<<"\nCheck Number : "<<i+1<<endl;
ck[i].check = i+1;
cout<<"\nEnter receipent name : ";
getline(cin,ck[i].receipent);
cout<<"\nEnter amount : ";
cin>>ck[i].amount;
cout<<"\nDate of check : "<<CurrentDate<<endl;
ck[i].checkDate = CurrentDate;
cout<<"\nEnter Comment for check : ";
getline(cin,ck[i].comment);
if(!cbook.writeCheck(ck[i]))
{
cout<<"\n\nNot enough balance "<<ck[i].amount<<endl<<endl;
}
else
i++;
break;
case 2:
cout<<"\n\nDetails of Last Check\n\n";
cout<<"*************************";
for(j = i-1;j>=0;j--)
{
cout<<"\nCheck Number : "<<ck[j].check;
cout<<"\nDate of Check : "<<ck[j].checkDate;
cout<<"\nReceipent : "<<ck[j].receipent;
cout<<"\nAmount on Check : "<<ck[j].amount;
cout<<"\nComment : "<<ck[j].comment;
cout<<"\n*************************\n";
}
break;
case 3:
cout<<"\nEnter amount to deposit : ";
cin>>Deposit;
cbook.deposit(Deposit);
break;
case 4:
cout << fixed << showpoint << setprecision( 3 );
cout << "Current Balance is: " << cbook.getBalance( )<<" " << endl;
break;
default:
if(choice!=5)
cout<<"\n\nInvalid Entry, please try again\n";
}
}while(choice!=5);
return 0;
}
So far all i know is that i need to do this.
Check ck[100]; -> std::vector<Check> ck;

Answer 1

After a quick glance at your code I believe this is the only thing you have to do:
Replace
struct Check ck[100];
with:
std::vector<Check> ck(100);
Or since you have a fixed-size array you could use std::array like this:
std::array<Check,100> ck;

Answer 2

You can declare a local variable, in the main: Check tmp;
And the vector as: std::vector<Check> ck;
when adding new check you work on the local tmp, and when successfully done, add it to the vector.
in your code:
if(!cbook.writeCheck(tmp)){
cout<<"\n\nNot enough balance "<<tmp.amount<<endl<<endl;
}else{
ck.push_back(tmp);
}
Also, you don't need to keep the count or index, since you can use ck.size().

Answer 3

iterate over the ck[] and push_back every item.something like this.
std::vector<Check> ckvector;
for(int i=0;i<100;i++)
ckvector.push_back(ck[i]);