Promise.all等待所有Promise執行完成

代碼示例

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
});

參考
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise/all