javascript - 使用包含异步等待的数组 foreach 等待

Question

这个问题在这里已经有了答案:





Using async/await with a forEach loop

(33 个答案)


6 个月前关闭。




在 node.js 中，我需要使用 function procesMultipleCandidates ()其中包含 Array.foreach 进程将每个元素插入数据库。但是整个函数应该在完成所有插入操作后返回响应
JavaScript 代码

async function procesMultipleCandidates (data) {
  let generatedResponse = []
  await data.forEach(async (elem) => {
    try {    
          
           // here candidate data is inserted into  
           let insertResponse = await insertionInCandidate(elem) 
           //and response need to be added into final response array 
           generatedResponse.push(insertResponse)
    } catch (error) {
    console.log('error'+ error);
    }
  })
  console.log('complete all') // gets loged first
  return generatedResponse // return without waiting for process of 
}

如上所述，最后一个返回语句不等待 foreach执行首先完成。

Answer 1

使用Array.prototype.map和 Promise.all :

async function procesMultipleCandidates (data) {
  let generatedResponse = []
  await Promise.all(data.map(async (elem) => {
    try {
      // here candidate data is inserted into  
      let insertResponse = await insertionInCandidate(elem)  
      // and response need to be added into final response array 
      generatedResponse.push(insertResponse)
    } catch (error) {
      console.log('error'+ error);
    }
  }))
  console.log('complete all') // gets loged first
  return generatedResponse // return without waiting for process of 
}

或使用 for/of 如果您不希望循环运行，则循环 concurrently :

async function procesMultipleCandidates (data) {
  let generatedResponse = []
  for(let elem of data) {
    try {
      // here candidate data is inserted into  
      let insertResponse = await insertionInCandidate(elem)  
      // and response need to be added into final response array 
      generatedResponse.push(insertResponse)
    } catch (error) {
      console.log('error'+ error);
    }
  }
  console.log('complete all') // gets loged first
  return generatedResponse // return without waiting for process of 
}