考虑一下这个
python代码
it = iter([1,2,3,4,5]) for x in it: print x if x == 3: break print '---' for x in it: print x
它打印1 2 3 — 4 5,因为迭代器会记住它在循环中的状态.当我在JS中看似相同的事情时,我得到的只是1 2 3 —.
function* iter(a) { yield* a; } it = iter([1,5]) for (let x of it) { console.log(x) if (x === 3) break } console.log('---') for (let x of it) { console.log(x) }
我错过了什么?
解决方法
@H_502_13@ 不幸的是,JS中的Generator对象不可重用.在 MDN清楚地说明
Generators should not be re-used,even if the for…of loop is terminated early,for example via the break keyword. Upon exiting a loop,the generator is closed and trying to iterate over it again does not yield any further results.