Basically I want to create an array of objects with a size which is passed through from one class to another i.e.
Object * ArrayOfObjects = new Object[Size];
Whilst that creates an array successfully, it doesnt allow me to use constructors.
How can I create an array of my objects then define each object in the array?
Once you allocate memory for the array you can then assign to it by looping:
for (int i = 0; i < Size; ++i)
{
ArrayOfObjects[i] = Object( /* call the constructor */ );
}
Or you can use a vector to do the same but with more ease of use:
std::vector<Object> ArrayOfObjects = { Object(...), Object(...) };
What you're asking may not actually be the best thing to do - which would be to use something like std::vector or something, but under the hood what they're going to do is what your question asks about anyway.
Then you can either assign or placement new each entry:
for (size_t i = 0; i < Size; ++i)
{
// Option 1: create a temporary Object and copy it.
ArrayOfObjects[i] = Object(arg1, arg2, arg3);
// Option 2: use "placement new" to call the instructor on the memory.
new (ArrayOfObjects[i]) Object(arg1, arg2, arg3);
}
Once you allot memory, as you did. You initialize each object by traversing the array of objects and call its constructor.
#include<iostream>
using namespace std;
class Obj
{
public:
Obj(){}
Obj(int i) : val(i)
{
cout<<"Initialized"<<endl;
}
int val;
};
int allot(int size)
{
Obj *x= new Obj[size];
for(int i=0;i<10;i++)
x[i]=Obj(i);
//process as you need
...
}
