Promise3.js

const timeoutPromise = (sec, msg) => {
  return new Promise((resolve, reject) => {
    setTimeout(()=>{
        console.log(msg);
        resolve();
    },sec)
  });
}

timeoutPromise(4000,"4秒経過")
.then(() => timeoutPromise(3000,"7秒経過"))
.then(() => timeoutPromise(2000,"9秒経過"))
.then(() => timeoutPromise(1000,"10秒経過"))