In programming languages, an abstract type is a type in a nominative type system that can be instantiated directly; a type that is not abstract – which can be instantiated – is called a concrete type.
举一反三
- Every instance of an abstract type is an instance of some concrete subtype.
- Anew type ________. A: is a subclass B: can be derived from an existing type C: can’t be called a derived type D: inherits all features of existing type and has additional features
- Abstracts are classified into different types, which of the following is not listed as one type of abstract? A: Expository abstract B: Structured abstract C: Informative abstract
- An induction motor's rotor can be either wound type or ????????-???? type.
- One of the parents is type A and the other is type B. the possible blood type of their children is A: It can only be type AB B: It can only be type A or type B C: It can only be type A, B and AB D: Type A, B, AB, O E: It can only be type AB or type O