<script> new Promise((resolve,reject) => { setTimeout(()=>{ resolve('sss'); },1000); }).then((data) =>{ console.log(data);//注意,此处不能写异步回调,异步必须写在下面的promise方法体内部,否则会有问题 return new Promise(resolve => { resolve(data + "bbb"); }); }).then(data =>{ console.log(data) }); </script>
还有一个Promise.all方法
Promise.all([ new Promise((resolve, reject) => { setTimeout(() => { resolve(null); }, 1000); }), new Promise((resolve, reject) => { setTimeout(() => { resolve(null); }, 3000); }) ]).then(result => { alert("ok"); });