javascript 链式承诺电话

Posted 2021-05-04

var asyncAdd = (a, b) => {
  return new Promise((resolve, reject) => {
    setTimeout(() => {
      if (typeof a === "number" && typeof b === "number") {
        resolve(a + b);
      } else {
        reject("Inputs must both br numbers");
      }
    }, 2000);
  });
};

asyncAdd(12, 8)
  .then(res => {
    console.log("Result:", res);
    return asyncAdd(res, 33);
  })
  .then(res => {
    console.log("Result:", res);
    return asyncAdd(res, 100);
  })
  .then(res => {
    console.log("Final result: ", res);
  })
  .catch(errorMessage => {
    console.log(errorMessage);
  });