Method isUndefined

mini_program/common/Tools.js:216–218

* 判断某个元素是否为undefined * @param {undefined} value * @return {Boolean}

(value)

	 * @return {Boolean}
	 */
	isUndefined(value) {
		return typeof value === 'undefined'
	}

	/**
	 * 判断某个元素是否为null