Promise常见方法

Promise语法

new Promise((resolve, reject) => {
        resolve('OK')  //成功
        resolve('err')  //失败
      })

Promise.all 包含的promise所有的成功返回成功，一个失败返回失败

const p1 = new Promise((resolve, reject) => {
        resolve('OK')
      })
      const p2 = new Promise((resolve, reject) => {
        resolve('OK')
      })
      const p3 = new Promise((resolve, reject) => {
        reject('err')
      })
      Promise.all([p1, p2, p3]).then(res => {
        console.log(res)
      })

Promise.any包含的promise一个成功返回成功，所有的失败返回失败

const p1 = new Promise((resolve, reject) => {
        resolve('OK')
      })
      const p2 = new Promise((resolve, reject) => {
        resolve('OK')
      })
      const p3 = new Promise((resolve, reject) => {
        reject('err')
      })
      Promise.any([p1, p2, p3]).then(res => {
        console.log(res)
      })

Promise.race包含的promise哪一个先返回结果就返回它的状态

const p1 = new Promise((resolve, reject) => {
        resolve('OK')
      })
      const p2 = new Promise((resolve, reject) => {
        resolve('OK')
      })
      const p3 = new Promise((resolve, reject) => {
        reject('err')
      })
      Promise.race([p1, p2, p3]).then(res => {
        console.log(res)
      })