import Optional from './Optional';
declare class ArrayUtils {
    private static readonly instance;
    private constructor();
    /**
     * If the item is an array, then push the flattened array into the result array, otherwise push the
     * item into the result array.
     *
     * @template T - The type of the elements in the array.
     * @param {any[]} arr - any[] - The array to flatten.
     */
    flat<T>(arr: Array<T | T[]>): T[];
    /**
     * It takes two arrays of the same type and returns an array of that type containing the elements
     * that are common to both arrays
     *
     * @template T - The type of the elements in the array.
     * @param {T[]} a - T[] - The first array to compare
     * @param {T[]} b - T[]
     * @returns An array of the elements that are in both a and b.
     */
    intersection<T>(a: T[], b: T[]): T[];
    /**
     * It takes two arrays, concatenates them, removes duplicates, and returns the result
     *
     * @template T - The type of the elements in the array.
     * @param {T[]} a - T[] - The first array to union
     * @param {T[]} b - T[]
     * @returns An array of unique values from both arrays.
     */
    union<T>(a: T[], b: T[]): T[];
    /**
     * It takes two arrays, and returns an array of all the elements in the first array that are not in
     * the second array
     *
     * @template T - The type of the elements in the array.
     * @param {T[]} a - T[] - The first array
     * @param {T[]} b - T[] - The array to compare against
     * @returns The difference between two arrays.
     */
    difference<T>(a: T[], b: T[]): T[];
    /**
     * This function takes an array of any type and shuffles it in place.
     *
     * @template T - The type of array to shuffle
     * @template X - The type of the elements in the array.
     * @param {T | X[]} array - T | X[]
     */
    shuffle<X, T extends Array<X>>(array: T | X[]): void;
    /**
     * It takes an array and a value, and returns the number of times the value occurs in the array.
     *
     * @template T - The type of the elements in the array.
     * @param {T[]} array - T[] - The array to search in
     * @param {T} value - T - The value to count occurrences of.
     * @returns The number of occurrences of the value in the array.
     */
    countOccurrences<T>(array: T[], value: T): number;
    /**
     * It clears an array by setting its length to zero
     *
     * @template T - The type of the elements in the array.
     * @param {any[]} array - any[]
     */
    clear(array: unknown[]): void;
    /**
     * It takes an array of any type, and returns a new array of the same type
     *
     * @template T - The type of the elements in the array.
     * @param {T[]} array - T[] - The array to clone.
     * @returns A new array with the same elements as the original array.
     */
    clone<T>(array: T[]): Array<T>;
    /**
     * It takes an array of any type, and returns a new array of the same type
     *
     * @template T - The type of the elements in the array.
     * @param {T[]} array - T[] - The array to clone.
     * @returns A new array with the same elements as the original array.
     */
    deepClone<T>(array: T[]): Array<T>;
    /**
     * It takes an array of any type, and returns an array of the same type, with all duplicates
     * removed
     *
     * @template T - The type of the elements in the array.
     * @param {T[]} arr - T[] - The array to remove duplicates from.
     * @returns A new array with the duplicates removed.
     */
    removeDuplicates<T>(arr: T[]): T[];
    /**
     * Sort an array of objects by a key of your choice.
     *
     * @template T - The type of the elements in the array.
     * @param {T[]} arr - T[] - The array to sort
     * @param key - keyof T
     * @returns An array of objects.
     */
    sortByKey<T extends object>(arr: T[], key: keyof T): T[];
    /**
     * It takes an array and an item, and returns a new array with the item removed
     *
     * @template T - The type of the elements in the array.
     * @param {T[]} arr - T[] - The array to remove the item from
     * @param {T} item - The item to remove from the array.
     * @returns A new array with all the items that are not equal to the item passed in.
     */
    remove<T>(arr: T[], item: T): T[];
    /**
     * It takes two arrays of different types and returns an array of tuples
     *
     * @template T - The type of the elements in the first array.
     * @template U - The type of the elements in the second array.
     * @param {T[]} arr1 - T[]
     * @param {U[]} arr2 - U[]
     * @returns An array of tuples.
     */
    zip<T, U>(arr1: T[], arr2: U[]): [T, U][];
    /**
     * It takes an array, an index, and any number of items, and returns a new array with the items
     * inserted at the index.
     *
     * @template T - The type of the elements in the array.
     * @param {T[]} arr - T[] - The array to insert into
     * @param {number} index - The index where you want to insert the items.
     * @param {T[]} items - T[] - The items to insert into the array.
     * @returns a new array with the items inserted at the specified index.
     */
    insert<T>(arr: T[], index: number, ...items: T[]): T[];
    /**
     * It takes an array and returns a new array with all the unique sub-arrays.
     * @param {any[][]} arr - any[][] - The array to get the unique sub-arrays from.
     * @returns A new array with all the unique sub-arrays.
     */
    uniqueSubArrays(arr: unknown[][]): unknown[][];
    /**
     * Finds the k-th smallest element in an array using the QuickSelect algorithm.
     *
     * @param {number[]} arr - The input array.
     * @param {number} k - The index of the desired smallest element (1-based).
     * @returns {number} The k-th smallest element in the array.
     */
    quickSelect(arr: number[], k: number): number;
    /**
     * Sorts an array in ascending order using the Quick Sort algorithm.
     *
     * @template T - The type of the elements in the array.
     * @param {T[]} arr - The input array to be sorted.
     * @param {Function} compareFn - A function to compare two elements.
     * @returns {T[]} The sorted array.
     */
    quickSort<T>(arr: T[], compareFn: (a: T, b: T) => number): T[];
    /**
     * Splits an array into smaller arrays of a specified size.
     *
     * @template T - The type of the elements in the array.
     * @param {T[]} array - The array to be chunked.
     * @param {number} chunkSize - The size of each chunk.
     * @returns {T[][]} - An array of smaller arrays (chunks).
     */
    chunks<T>(array: T[], chunkSize: number): T[][];
    /**
     * Returns the found element or undefined in an Optional
     *
     * @template T - The type of the elements in the array.
     * @param array the array to be searched
     * @param property the property to be searched in
     * @param value the value to be searched for
     * @returns Optional object of the value
     */
    findByPropertyValue<T>(array: T[], property: keyof T, value: unknown): Optional<T>;
    /**
     * Returns the index of the first occurrence of a given value in an array.
     *
     * @template T - The type of the elements in the array.
     * @param array the array to search in
     * @param property the property to search on
     * @param value the value to search for
     * @returns the index of the value in the array, or -1 if not found
     */
    findIndexByPropertyValue<T>(array: T[], property: keyof T, value: unknown): number;
    /**
     * @template T - The type of the elements in the array.
     * @param array the array to search
     * @param condition the condition to search for
     * @returns the indicies found in the array
     */
    findAllIndices<T>(array: T[], condition: (element: T) => boolean): number[];
    static getInstance(): ArrayUtils;
}
declare const _default: ArrayUtils;
export default _default;