Declare an array of objects using a for loop c++

问题

Okay. So I have declared an array of objects, and I have manually defined them using this code:

Object* objects[] =
{
    new Object(/*constructor parameters*/),
    new Object(/*constructor parameters*/)
}; 

Is there anyway to use some kind of a loop (preferably a for loop) to declare these? Something like:

Object* objects[] =
{
    for(int i=0; i<20; /*number of objects*/ i++)
    {
        new Object(/*constructor parameters*/);
    }
}; 

But with proper syntax?

回答1:

I strongly suggest using a standard library container instead of arrays and pointers:

#include <vector>

std::vector<Object> objects;

// ...

void inside_some_function()
{
    objects.reserve(20);
    for (int i = 0; i < 20; ++i)
    {
        objects.push_back(Object( /* constructor parameters */ ));
    }
}

This provides exception-safety and less stress on the heap.

回答2:

Object* objects[20];

for(int i=0; i<20; /*number of objects*/ i++)
{
    objects[i] = new Object(/*constructor parameters*/);
}

回答3:

Points in C++ can be used as arrays. Try something like this:

// Example
#include <iostream>

using namespace std;

class Object
{
public:
    Object(){}
    Object(int t) : w00t(t){}
    void print(){ cout<< w00t << endl; }
private:
    int w00t;
};

int main()
{
    Object * objects = new Object[20];
    for(int i=0;i<20;++i)
        objects[i] = Object(i);

    objects[5].print();
    objects[7].print();

    delete [] objects;
    return 0;
}

Regards,
Dennis M.

来源：https://stackoverflow.com/questions/5226352/declare-an-array-of-objects-using-a-for-loop-c