为什么将“ any”类型的对象设置为具有特定类型的属性不会引发TS编译错误？

Question

Why this code is not throwing any Typescript errors (see TS playground ):

interface ErrorData {
    code: number;
    message: string;
}

interface EnrichedError {
    description: string;
    error: ErrorData;
}

const a: any = "bla bla bla";
const b: EnrichedError = {
    description: 'this is a test',
    error: a
}

Why it's possible to set b.error to a?

Answer 1

Because that's the point of any , it is assignable to all types, and all types are assignable to it.

It is your escape hatch, it basically tells TypeScript that "this value can go anywhere"