text: /**
   * get the type of variable
   * @param variable
   * @returns {string}
   */
  function what(variable) {
      // null and undefined
      if (variable === null) return 'null';
      if (variable === undefined) return 'undefined';
      let type = typeof variable;
      // common type
      if (
          type === 'string' ||
          type === 'number' ||
          type === 'function' ||
          type === 'boolean'
      ) return type;
      // other objects
      return ({}).toString.call(variable).slice(8, -1).toLowerCase();
  }
  
  module.exports = what;