/**
 * Converts `string`, as space separated words, to lower case.
 *
 * @since 5.6.0
 * @category String
 * @param str The string to convert.
 * @returns Returns the lower cased string.
 * @see camelCase, kebabCase, snakeCase, startCase, upperCase, upperFirst
 * @example
 *
 * ```js
 * lowerCase('--Foo-Bar--')
 * // => 'foo bar'
 *
 * lowerCase('fooBar')
 * // => 'foo bar'
 *
 * lowerCase('__FOO_BAR__')
 * // => 'foo bar'
 * ```
 */
export declare function lowerCase(str: string): string;
export default lowerCase;