Question

I have a following class foo

class foo
{
    int *arr; // arr holds numbers
    int sz; // size of array
    public:
    // Suppose I have made default and 1 parameter c'tor
    foo(const foo &f)
    {
        sz = f.sz;
        arr = new int[sz];
        for(int i=0;i<sz;i++)
            arr[i]=f.arr[i];
    }
};

int main()
{
    foo x(5); //5 is size of array
    const foo y = x; //doesn't work as I haven't initialized in member-initialization list, but how to write for loop in member initialization list ?
}  

So How do I write for loop in member initialization list ?

Answer 1

You could just use a std::vector in this case… anyways.

Typically, I will create a private static method which will perform the allocation and copy. Then the initialization list may be used:

static int* CloneInts(const foo& f) {
    int* ints = new ...
    ...copy them from @a f.arr...
    return ints;
}

Then your init-list would look like:

foo(const foo& f) : arr(CloneInts(f)), sz(f.sz) {