Do arrays and array size declarators need to be the same data type?

Question

I'm studying basic programming logic and design, and an example question uses pseudocode declaring an integer-type size declarator in a real-type array. Am I wrong for thinking this to be incorrect due to different data types, or can a real-type array use an integer-type constant as a size declarator? Thank you in advance for any insight.

Answer 1

Array size is an integer. An array of objects can't have 11.25732 elements or "kitten" elements except maybe in Prolog :)

The exact type of integer depends on the language, for example an unsigned 32-bit.

Generally an array of any type can be accessed using [ix] where ix is an integer of some type, such as size_t for c++.

In some languages arrays are key => value pairs where animals["kitten"] does work, but the size or count is still integer. Then arrays might be sparse, where [1] and [100] hold values but [2] - [99] are currently undefined.