forOwn

[jingchaocheng]

使用 iteratee 遍历自身的可枚举属性。 iteratee 会传入3个参数：(value, key, object)。 如果返回 false，iteratee 会提前退出遍历。

/**
 * Iterates over own enumerable string keyed properties of an object and
 * invokes `iteratee` for each property. The iteratee is invoked with three
 * arguments: (value, key, object). Iteratee functions may exit iteration
 * early by explicitly returning `false`.
 *
 * @since 0.3.0
 * @category Object
 * @param {Object} object The object to iterate over.
 * @param {Function} iteratee The function invoked per iteration.
 * @see forEach, forEachRight, forIn, forInRight, forOwnRight
 * @example
 *
 * function Foo() {
 *   this.a = 1
 *   this.b = 2
 * }
 *
 * Foo.prototype.c = 3
 *
 * forOwn(new Foo, function(value, key) {
 *   console.log(key)
 * })
 * // => Logs 'a' then 'b' (iteration order is not guaranteed).
 */
function forOwn(object, iteratee) {
  // new Object(object)
  object = Object(object)

  // 获取 object 的自身属性遍历
  // 调用 iteratee 传入当前项、索引和 object 
  Object.keys(object).forEach((key) => iteratee(object[key], key, object))
}

export default forOwn