Promise()

【Promise()】

　　The constructor is primarily used to wrap functions that do not already support promises.

executor

　　A function that is passed with the arguments resolve and reject. The executor function is executed immediately by the Promise implementation, passing resolve and reject functions (the executor is called before the Promiseconstructor even returns the created object). 

　　红字部分：executor在new Promise()返回前就被执行。

A Promise is in one of these states:

• pending: initial state, neither fulfilled nor rejected.
• fulfilled: meaning that the operation completed successfully.
• rejected: meaning that the operation failed.

参考：https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise

Promise()

原文：http://www.cnblogs.com/tekkaman/p/7496938.html