Promise race 机制

 

race机制，我们今天直接上例子，上结果

 

let p1 = new Promise((resolve, reject) => {

setTimeout(() => {
resolve('i am p1')
console.log('i am p1')
}, 6000);
})

let p2 = new Promise((resolve, reject) => {
setTimeout(() => {
reject('i am p2')
console.log('i am p2')
}, 5000);
}).catch(e=>{
console.log('p2-catch',e)
throw e
})

Promise.race([p1, p2]).then((result) => {
console.log(result,'race-then')
}).catch((error) => {
console.log(error,'race-catch')
})

结果

i am p2

 p2-catch i am p2

 i am p2 race-catch

 i am p1