/**
 * Iterates over each element of the array invoking the provided callback function for each element.
 *
 * @template K - The type of elements in the array.
 * @template T - The type of the array.
 * @param {T | null | undefined} array - The array to iterate over.
 * @param {(value: K, index: number, array: T) => unknown} [callback] - The function invoked for each element.
 * The callback function receives three arguments:
 *  - 'value': The current element being processed in the array.
 *  - 'index': The index of the current element being processed in the array.
 *  - 'array': The array 'forEach' was called upon.
 * @returns {T} Returns the original array.
 *
 * @example
 * forEach([1, 2, 3], (value, index, array) => console.log(value, index));
 * // Output:
 * // 1 0
 * // 2 1
 * // 3 2
 *
 */
declare function forEach<T>(array: T[], callback?: (value: T, index: number, array: T[]) => unknown): T[];
/**
 * Iterates over each element of the array invoking the provided callback function for each element.
 *
 * @template K - The type of elements in the array.
 * @template T - The type of the array.
 * @param {T | null | undefined} array - The array to iterate over.
 * @param {(value: K, index: number, array: T) => unknown} [callback] - The function invoked for each element.
 * The callback function receives three arguments:
 *  - 'value': The current element being processed in the array.
 *  - 'index': The index of the current element being processed in the array.
 *  - 'array': The array 'forEach' was called upon.
 * @returns {T} Returns the original array.
 *
 * @example
 * forEach([1, 2, 3], (value, index, array) => console.log(value, index));
 * // Output:
 * // 1 0
 * // 2 1
 * // 3 2
 *
 */
declare function forEach<T>(array: readonly T[], callback?: (value: T, index: number, array: T[]) => unknown): readonly T[];
/**
 * Iterates over each element of the array invoking the provided callback function for each element.
 *
 * @template T - The type of string.
 * @param {T | null | undefined} string - The string to iterate over
 * @param {(value: T, index: number, string: T) => unknown} [callback] - The function invoked for each char.
 * The callback function receives three arguments:
 *  - 'char': The current char being processed in the string.
 *  - 'index': The index of the current char being processed in the string.
 *  - 'string': The string 'forEach' was called upon.
 * @returns {T} Returns the original string.
 *
 * @example
 * forEach('abc', (char, index, string) => console.log(char, index));
 * // Output:
 * // 'a' 0
 * // 'b' 1
 * // 'c' 2
 */
declare function forEach<T extends string | null | undefined>(string: T, callback?: (char: string, index: number, string: string) => unknown): T;
/**
 * Iterates over each element of the array invoking the provided callback function for each element.
 *
 * @template T - The type of elements in the array.
 * @param { ArrayLike<T> } array - The array to iterate over.
 * @param {(value: T, index: number, array: ArrayLike<T>) => unknown} [callback] - The function invoked for each element.
 * The callback function receives three arguments:
 *  - 'value': The current element being processed in the array.
 *  - 'index': The index of the current element being processed in the array.
 *  - 'array': The array 'forEach' was called upon.
 * @returns {T} Returns the original array.
 *
 * @example
 * forEach([1, 2, 3], (value, index, array) => console.log(value, index));
 * // Output:
 * // 1 0
 * // 2 1
 * // 3 2
 *
 */
declare function forEach<T>(array: ArrayLike<T>, callback?: (value: T, index: number, array: ArrayLike<T>) => unknown): ArrayLike<T>;
/**
 * Iterates over each element of the object invoking the provided callback function for each property.
 *
 * @template T - The type of object.
 * @param {T} object - The object to iterate over.
 * @param {(value: T[keyof T], key: keyof T, object: T) => unknown} [callback] - The function invoked for each property.
 * The callback function receives three arguments:
 *  - 'value': The current property being processed in the object.
 *  - 'key': The key of the current property being processed in the object.
 *  - 'object': The object 'forEach' was called upon.
 * @returns {T} Returns the original object.
 *
 * @example
 * forEach({'a': 1, 'b': 2 }, (value, key, object) => console.log(value, key));
 * // Output:
 * // 1 'a'
 * // 2 'b'
 */
declare function forEach<T extends object | null | undefined>(object: T, callback?: (value: T[keyof T], key: keyof T, object: T) => unknown): T;

export { forEach };