Promise.all等待所有Promise执行完成

const promise1 = new Promise((resolve, reject) => {
  setTimeout(() => {
    resolve("func1");
  }, 1000);
});
const promise2 = new Promise((resolve, reject) => {
  setTimeout(() => {
    resolve("func1");
  }, 1000);
});
Promise.all([promise1, promise2]).then((ret) => {
  console.log(ret);
  // [ 'func1', 'func1' ]
  const [ret1, ret2] = ret;
  console.log(ret1, ret2);
  // func1 func1
});