/**
 * @name arrayFilter
 * @summary Filters undefined and (optionally) null values from an array
 * @description
 * Returns a new array with all `undefined` values removed. Optionally, when `allowNulls = false`, it removes the `null` values as well
 * @example
 * <BR>
 *
 * ```javascript
 * import { arrayFilter } from '@polkadot/util';
 *
 * arrayFilter([0, void 0, true, null, false, '']); // [0, true, null, false, '']
 * arrayFilter([0, void 0, true, null, false, ''], false); // [0, true, false, '']
 * ```
 */
export declare function arrayFilter<T = unknown>(array: readonly (T | null | undefined)[], allowNulls?: boolean): T[];