Difference between ES6 and Promise/A+ specifications

Question

Mainly the difference between then methods

A is relatively easy to read. I still don’t understand the es6 specification about then. It seems that the return value of the callback function is not classified and processed

This is just one of the doubts. Is there any pioneer who can explain the comprehensive differences in detail?

Answer 1

I don’t quite understand what the poster wants to ask

I understand yes

Promise/A+ is one of the specifications of Promise, and for specific use, browsers, node, and JS libraries need to implement corresponding functions according to this specification.

ES6’s Promise is an implementation of the Promise/A+ specification, and some additional simple methods such as Promise.all and Promise.race are added based on the specification implementation

Similarly, existing JS libraries such as es6-promise,bluebrid also implement the Promise/A+ specification