承诺不等到完成

本文介绍了承诺不等到完成的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

我今天看了很多例子.他们似乎建议以下代码应按链执行:

I looked at many examples today. They seem to suggest that the following code should be executed in chain:

let f = () => { return new Promise((res, rej) => { console.log('entering function'); setTimeout(() => { console.log('resolving'); res() }, 2000) }); }; Promise.resolve() .then(f()) .then(f());

预期输出为:

entering function resolving entering function resolving

但不是.输出是

entering function entering function resolving resolving

，我不知道为什么.任何帮助将不胜感激.

and I can't figure out why. Any help will be much appreciated.

推荐答案

尝试使用then(f)而不是then(f())

then需要一个功能.

您也可以执行then(()=>f())