该函数接收一个 array 作为输入参数，遍历这个 array，将其每个元素，作为另一个匿名函数执行的一部分。该匿名函数体内，将 array 的元素作为 subscriber 订阅函数的输入：
<html> <script> const subscribeToArray = (array) => (subscriber) => { for (let i = 0, len = array.length; i < len && !subscriber.closed; i++) { subscriber.next(array[i]); } subscriber.complete(); }; const aInput = [1,2,3,4]; const newFunction = subscribeToArray(aInput); debugger; </script> </html>
<html> <script> const subscribeToArray = (array) => (subscriber) => { for (let i = 0, len = array.length; i < len && !subscriber.closed; i++) { subscriber.next(array[i]); } subscriber.complete(); }; const aInput = [1,2,3,4]; const newFunction = subscribeToArray(aInput); const subscriber = { closed: false }; subscriber.next = (data) => console.log("next: " + data); subscriber.complete = () => console.log("completed!"); debugger; newFunction(subscriber); </script> </html>
直到应用程序代码调用 Observable 的 subscribe 方法时，才会变量 input 数组，用 subscribe 的 next 方法依次处理 input 数组的元素。在 CombineLatest Operator 的例子里，input 元素就是 Observable 对象的组合。
