Capitalize the first letter of a string, or all words in a string

capitalize.js

/**
 * Capitalize the first letter of a string, or all words in a string.
 *
 * @param {string}
 * @returns {string}
 * @example
 *
 * capitalize('foo bar baz');
 * => "Foo bar baz"
 *
 * capitalize.words('foo bar baz');
 * => "Foo Bar Baz"
 */

function capitalize(str) {
  return str.charAt(0).toUpperCase() + str.substring(1);
}

capitalize.words = function words(str) {
  return str.split(/\s+/).map(capitalize).join(' ');
};