Question

I understand “How to convert vector to array in C++“

answers how to convert a vector of doubles (NON POINTER TYPE) to an array.

My requirement :: To convert (a vector of CustomClass pointers) to (a CustomClass pointer to an array of CustomClass pointers).

Does the following code mean “(vector of pointers) –> (Pointer to an array of CustomClass pointers)”

std::vector <CustomClass*> vectorObject(SizeOfVector);  // Here each element of the vector //is a pointer to CustomClass object.
CustomClass* customClassArray = &vectorObject[0];

Please correct me if I am wrong. Kindly Help with a code snippet.

Thanks in advance.

Answer 1

Vector is a wrapper in a sorts for an array and provides all the features of an array whilst also allowing the array to grow shrink know how big it is and a lot of other useful features. One of the requirements of std vector is that its data is stored in a contiguous fashion like an array. Because of this requirement you can get an array of elements by taking the address of the first element regardless of type.

std::vector <CustomClass*>vectorObject Means that you have a vector of CustomClass Pointers to get an array

CustomClass **Array = &vectorObject[0] Now I have taken the contiguous data segment at offset 0 in the vector and assigned it the a pointer pointer of customclass remember that arrays and pointers are deeply connected in c and c++ I can now access the pointer pointer as if it were an array

CustomClass * FirstEle = Array[0];