T5 ​

setTimeout(() => {
        console.log("0")
}, 0)
new Promise((resolve,reject)=>{  // Promise 1
    console.log("1")
    resolve()
}).then(()=>{        // Promise 1 的回调
    console.log("2")
    new Promise((resolve,reject)=>{	// Promise 2
      console.log("3")
      resolve()
    }).then(()=>{      // Promise 2 的回调
      console.log("4")
    }).then(()=>{      // Promise 2 的回调的回调
      console.log("5")
    })
}).then(()=>{  	// Promise 1 的回调的回调
    console.log("6")
})
    
new Promise((resolve,reject)=>{ // Promise 3
    console.log("7")
    resolve()
    }).then(()=>{         // Promise 3 的回调
    console.log("8")
})

1
7 
2
3
8
4
6
5
0