function Promise(executor){
//resolve和reject都是函数
//添加属性
this.PromiseState = "pending";
this.PromiseResult = null
const self = this;
//resolve函数
function resolve(data){
//(1)修改对象的状态
//this.PromiseState //这里的this为window,因为resolve是直接调用的
self.PromiseState = 'fulfilled'
//(2)设置对象结果值
self.PromiseResult = data
}
//reject函数
function reject(data){
//(1)修改对象的状态
self.PromiseState = 'rejected'
//(2)设置对象结果值
self.PromiseResult = data
}
//同步调用执行器函数
try {
executor(resolve,reject)
}catch(e){
reject(e)
}
}
//添加then方法
Promise.prototype.then = function(onResolved,onRejected){
}