属性“propname”是“Class”类型的静态成员

Question

This code does not compile with typescript. It says Property 'say' is a static member of type 'Animal on line 11 (last).

Could someone please explain why?

class Animal {
    static say: string;
}
class Dog extends Animal{
    static say = 'bark'
}
class Cat extends Animal{
    static say = 'meow'
}
const animals:Animal[] = [Dog, Cat]
animals.filter(e=>e.say ==='meow')

Answer 1

You've narrowed the type on animals to be instances of those classes, not the classes themselves. Try this:

const animals: (typeof Animal)[] = [Dog, Cat];

or just leave off the type and let it be inferred;