Each page is an element of the array 'notebook'. Programmatically, you would retrieve information from a page by referring to its number or subscript, i.e., notebook(4) would refer to the contents of ...Each page is an element of the array 'notebook'. Programmatically, you would retrieve information from a page by referring to its number or subscript, i.e., notebook(4) would refer to the contents of page 4 of the array notebook. The number of elements in the array, also known as the size of the array, is n. Arrays are very efficient in most languages, as operations compute the address of an element via a simple formula based on the base address element of the array.