两个promise的小demo

1

const ispregant = true;
function pregantPromise() {
  return new Promise((resolve, reject) => {
    if (ispregant) {
      resolve("孩子他爹");
    } else {
      reject("老公");
    }
  });
}
pregantPromise().then(res=>{
  console.log(res);
}).catch(err=>{
  console.log(err);
}).finally(()=>{
  console.log('他们还是结婚了');
})

2

const Address='http://www.baoidu.com'
const addPromise=()=>{
  return new Promise((resolve,reject)=>{
    const img=new Image()
    img.src=url
    img.onload=()=>{
      resolve(img)
    }
    img.onerror=()=>{
      reject(new Error('图片有误'))
    }
  })
}
addPromise(Address).then(img=>{
  document.body.appendChild(img)
}).catch(err=>{
  document.body.innerHTML=err
})