const fs=require("fs")
let p=new Promise((resolve, reject)=>{
fs.readFile('./resource/1.html',(err,data)=>{
if(err) reject(err);
resolve(data)
})
})
let p2=p.then(value => {
return new Promise((resolve, reject)=>{
fs.readFile('./resource/2.html',(err,data)=>{
if(err) reject(err);
resolve([value,data])
})
})
},reason => {
});
let p3=p2.then(value => {
return new Promise((resolve, reject)=>{
fs.readFile('./resource/4.html',(err,data)=>{
if(err) reject(err);
value.push(data)
resolve(value)
})
})
},reason => {
})
p3.then(value => {
console.log(value.join(''))
})
