我正在研究QueryList类的定义。它包含私有属性QueryList，但没有方法来填充此属性。 angular如何填充export declare class QueryList<T> {
private _dirty;
private _results;
private _emitter;
readonly changes: Observable<any>;
readonly length: number;
readonly first: T;
readonly last: T;
/**
* See
* [Array.map](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/map)
*/
map<U>(fn: (item: T, index: number, array: T[]) => U): U[];
/**
* See
* [Array.filter](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/filter)
*/
filter(fn: (item: T, index: number, array: T[]) => boolean): T[];
/**
* See
* [Array.find](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/find)
*/
find(fn: (item: T, index: number, array: T[]) => boolean): T | undefined;
/**
* See
* [Array.reduce](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/reduce)
*/
reduce<U>(fn: (prevValue: U, curValue: T, curIndex: number, array: T[]) => U, init: U): U;
/**
* See
* [Array.forEach](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/forEach)
*/
forEach(fn: (item: T, index: number, array: T[]) => void): void;
/**
* See
* [Array.some](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/some)
*/
some(fn: (value: T, index: number, array: T[]) => boolean): boolean;
toArray(): T[];
toString(): string;
reset(res: Array<T | any[]>): void;
notifyOnChanges(): void;
/** internal */
setDirty(): void;
/** internal */
readonly dirty: boolean;
/** internal */
destroy(): void;
}
类的对象？
声明：
map<U>(fn: (item: T, index: number, array: T[]) => U): U[]
同样，我对地图的声明感到困惑，过滤...对于地图，只有一行：
color = "red"当然，map接受一个函数，但这只是签名。它如何知道如何处理参数函数？
我在这里明显缺少Angular的工作原理......