use of array in c++

use of array in c++

y in c++

#include<iostream>
#include<cstdlib>
class vector
{
private:
int *arr,size;
public:
{
vector(){size=0;}
vector( int sz)
{
size=sz;
arr=new int[size];
}
vector(int*a,int sz)
{
size=sz;
arr= new int[size];
for(int i=o;i<size;++i)
arr[i]=a[i];
}
voidadditem(int data)
{
int *temp;
temp=new int[size];
for(int i=o;i<size;++i)
temp[i]=arr[i];
delete[] arr;
arr=new int[++size];
for(i=o;i<size-1;++i)
arr[i]=temp[i];
delete[]temp;
}
int removeitem()
{
int *temp,res;
temp=new int[--size];
for(int i=0;i<size;++i)
temp[i]=arr[i];
res=arr[size];
delete[]arr;
arr=new int[size];
for(int i=o;i<size;++i)
arr[i]=temp[i];
delete []temp;
return res;
}
void readdata()
cout<<"enter data for "<<size<<"items<<endl;
for(int i=0;i<size;++i
cin>>arr[i];
}
void showdata()
{
cout<<"there are<<size<<"elements in vector"<<endl;
cout<<"they are:";
for(int i=0;i<size;++i)
cot<< arr[i]<<"\t";
cot<<endl;
}
};
int main()
int myarr[]={2,5,7,8,9,10};
vector v1(3);
v1.readdata();
v1.showdata();
vector v2(myarr,6);
v2.showdata();
v2.additem(24);
cout<<"after adding item";
v2.showdata();
cout<<"the item is:"<<v1.removeitem()<<endl;
cout<<"after removing item:";
v1.showdata();
system("pause")
return 0;
}