This is untrue. This is an Ada declaration for a fixed-size array of Foo with indices 1 to 10 (inclusive): type Foo_Array is array (Integer range 1..10) of

This is untrue. This is an Ada declaration for a fixed-size array of Foo with indices 1 to 10 (inclusive): type Foo_Array is array (Integer range 1..10) of Foo; This is an array indexed by an enumeration: type Foo_Array is array (Some_Enum) of Foo; But dynamically sized arrays can also be declared: type Foo_Array is array (Integer range <>) of Foo; Note that such an array has a dynamic lower bound and a dynamic upper bound. If I create an instance of such an array and pass it to a procedure: declare My_Array: Foo_Array (3..10) begin Do_Something (My_Array); end; then the procedure Do_Something receives both bounds of the array, 3 and 10, which it can read with the 'First and 'Last attributes. A declaration like the one above is typically done on the stack (although it doesn't have to be). An array can be allocated on the heap with "new", with, IIRC, the following syntax: new Foo_Array (3..10)