/**
 * @param {string} url
 * @returns {Boolean}
 */
function validURL(url) {
	const reg = /^(https?|ftp):\/\/([a-zA-Z0-9.-]+(:[a-zA-Z0-9.&%$-]+)*@)*((25[0-5]|2[0-4][0-9]|1[0-9]{2}|[1-9][0-9]?)(\.(25[0-5]|2[0-4][0-9]|1[0-9]{2}|[1-9]?[0-9])){3}|([a-zA-Z0-9-]+\.)*[a-zA-Z0-9-]+\.(com|edu|gov|int|mil|net|org|biz|arpa|info|name|pro|aero|coop|museum|[a-zA-Z]{2}))(:[0-9]+)*(\/($|[a-zA-Z0-9.,?'\\+&%$#=~_-]+))*$/
	return reg.test(url)
}

/**
 * @param {string} str
 * @returns {Boolean}
 */
function isString(str) {
	if (typeof str === 'string' || str instanceof String) {
		return true
	}
	return false
}

/**
 * @param {Array} arg
 * @returns {Boolean}
 */
function isArray(arg) {
	if (typeof Array.isArray === 'undefined') {
		return Object.prototype.toString.call(arg) === '[object Array]'
	}
	return Array.isArray(arg)
}

// 向外暴露接口
module.exports = {
	validURL,
	isString,
	isArray
}