export class Counter { private _min: number; private _max: number; private _last: number; constructor(min: number = 1, max: number = Number.MAX_SAFE_INTEGER) { this._min = min; this._max = max; this._last = max; } /** 复位:从新从0开始计数 */ reset() { this._last = this._max; } getNext() { return this._last >= this._max ? (this._last = this._min) : ++this._last; } getlast() { return this._last; } }