javascript - 使用 next() 时如何清除 Iterable 对象的当前位置？

Question

如何在 for 循环之后或使用 .next() 方法之后清除当前位置？

 const arr = [1,4,2];
 for(v of arr){
     // console.log(v); // 1 4 2
 }
 //  console.log(arr.next())  //arr.next is not a function

 /*
 * 
 * Why? because it is an iterable not an iterator,
 * and to be able to use .next we need to call the iterator method 
 * this iterable’s Symbol.iterator returns:
 * */
 const iter = arr[Symbol.iterator]();

 console.log(iter.next());
 console.log(iter.next());
 console.log(iter.next());
 console.log(iter.next());

此后我想从项目中获取 1 个值。

如何做到这一点？

此示例来自http://blog.dubizzle.com/boilerroom/2017/01/09/introduction-javascript-iterables-iterators-generators/

Answer 1

本身无法“清除当前位置”。但是，此答案中建议了有用的替代方案:Is it possible to reset an ECMAScript 6 generator to its initial state? .