Promise is a high-frequency question in front-end interviews. When I was an interviewer, the probability of asking Promise exceeded 90%. As far as I know, most companies would ask some questions about Promise. If you can write standard source code according to the standard of PromiseA+, then I think you can give perfect answers to ..
To know what it is and why it is, first understand three concepts: 1. What is synchronization? Synchronization means that when a “call” is issued, the “call” will not return until the result is obtained. But once the call returns, you get the return value. In other words, it is the “caller” who actively waits ..