angular_api1

angular基础api

angular.isNumber

/** * @ngdoc function * @name angular.isNumber * @module ng * @kind function * * @description * Determines if a reference is a `Number`. *判断一个引用是否是数字 * This includes the "special" numbers `NaN`, `+Infinity` and `-Infinity`. *包含特殊number NaN `+Infinity` and `-Infinity`. * If you wish to exclude these then you can use the native * [`isFinite'](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/isFinite) * method. * * @param {*} value Reference to check. * @returns {boolean} True if `value` is a `Number`. */
 * @ngdoc function
 * @name angular.isNumber
 * @module ng
 * @kind function
 *
 * @description
 * Determines if a reference is a `Number`.
 *判断一个引用是否是数字
 * This includes the "special" numbers `NaN`, `+Infinity` and `-Infinity`.
 *包含特殊number NaN `+Infinity` and `-Infinity`.
 * If you wish to exclude these then you can use the native
 * [`isFinite'](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/isFinite)
 * method.
 *
 * @param {*} value Reference to check.
 * @returns {boolean} True if `value` is a `Number`.
 */
function isNumber(value) {return typeof value === 'number';}

nextUid

/** * A consistent(一致的) way of creating unique IDs in angular. * * Using simple numbers allows us to generate 28.6 million unique ids per second for 10 years before * we hit number precision issues in JavaScript. * * Math.pow(2,53) 2的53次幂/ 60 / 60 / 24 / 365 / 10 = 28.6M * * @returns {number} an unique alpha-numeric string */
 * A consistent(一致的) way of creating unique IDs in angular.
 *
 * Using simple numbers allows us to generate 28.6 million unique ids per second for 10 years before
 * we hit number precision issues in JavaScript.
 *
 * Math.pow(2,53) 2的53次幂/ 60 / 60 / 24 / 365 / 10 = 28.6M
 *
 * @returns {number} an unique alpha-numeric string
 */
function nextUid() {
  return ++uid;
}

10年内每秒可以生成 28.6 million的唯一标识
js的精确整数最大为:Math.pow(2,53)-1 =9007199254740991.