export class TheoryCheck {
  public static isEmptyObj(obj: Object): boolean {
    return Object.keys(obj).length === 0;
  }

  public static isEmptyArray<T>(arr: Array<T> | HTMLCollectionOf<Element>): boolean {
    if (arr.length > 0) {
      return false;
    } else {
      return true;
    }
  }

  // 判断是否是 有效的
  public static isNullOrUndefined<T>(instance_: T) {
    if (instance_ !== null && instance_ !== undefined) {
      return false;
    } else {
      return true;
    }
  }
}