for循环和forEach在async的区别

js

for循环对await的请求是按先后顺序的，forEach的请求是并发请求的
function request () {
    return new Promise((resolve, reject) => {
      setTimeout(() => {
        resolve('666')
      }, 1000)
    })
  }
 async function geuli () {
   let arr = [request,request,request,request,request,request]
//   arr.forEach(async (value) => {
//     await value()
//   })
//   for(let i = 0; i < arr.length; i++) {
//    let ret = await arr[i]()
//     console.log(ret) //1s后每隔1s打印一次666
//   }
   arr.forEach(async (value) => {
    let ret =  await value()
     console.log(ret) //1s后同时打印6个 666
   })
 }