In C++, for what purpose is the rank() used?

Options

  • A. It returns the size of each dimension
  • B. It returns the maximum number of elements that can be stored in the array
  • C. It returns the dimension of the specified array
  • D. More than one of the above
  • E. None of the above

Correct Answer (Detailed Explanation is Below)

C. It returns the dimension of the specified array

Detailed Explanation

Answer: (C) It returns the dimension of the specified array

In C++, std::rank is a type trait defined in the <type_traits> header. It determines the number of dimensions of an array type at compile time.

For example, int arr[3][4] is a two-dimensional array, so std::rank<decltype(arr)>::value gives 2.

Similarly, int arr[2][3][4] has three dimensions, so its rank is 3.

Therefore, rank() is related to the number of array dimensions, not the size or number of elements in each dimension.