Question

我想寻求帮助！

我正在尝试对每个数组元素发出发布请求。

问题是我需要积累每个帖子响应的答案，然后将count数组返回给调用函数。我认为我的基本问题是返回的计数为0（已初始化），换句话说，发布请求尚未完成，答案已经返回。

我还认为我的代码太嵌套了，我需要帮助以简化请求

谢谢

function gt({ username, startDate, endDate }) {
  const query = '....' //never mind here 

  client.request(query, { username:arguments[0],
    startDate:arguments[1],
    endDate:arguments[2]})
      .then((response)=>{
        //response here is ok and what i expect then i want to send the response for proccesing and get the answer back in categories

        let count = getCategories(response["transactions"]);
// here is the wanted result should be in the returned answer
        console.log(count);
      })
      .catch((err)=>{console.log(err)});

}

function getCategories(transactions){

  let count = CATEGORIES; /// some json with keys and values
  Object.keys(count).forEach(v => count[v] = 0)  /// zero the values

  for (var i=0;i<transactions.length;i++){
    let transaction= transactions[i];
    axios.post(SERVER_URL, {
      transDescription: transaction["description"]
    })
        .then( function (response) {
          let category = response.data["transactionCategory"];
          console.log(category)
          count[category]+= transaction["amount"];}) //accumulating in count and then return when loop finishes
        .catch(function (error) {
          console.log(error);
        });
  }

  return count;
}

调用gt函数：


gt('some username','some date','some date'); 

// i expect to get the count variable here and print it

Answer 1

实际上，您的[ { "value_one_new_name": "Y", "value_two_new_name": "12", "key": "123" }, { "value_one_new_name": "N", "value_two_new_name": "2", "key": "123" }, { "value_one_new_name": "Y", "value_two_new_name": "35", "key": "456" } ]循环在任何for请求完成并且其诺言得以解决之前就结束了。

此外，您可能希望您的axios函数实际上返回一些值：对计数的承诺。

我建议使用gt和async，它们对于带有异步代码的循环非常实用。

注意：await是替代方法，但是您可能几乎同时发送了许多请求。

Promise.all

在function gt({ username, startDate, endDate }) { const query = "..."; return client.request(query, { // ^^^^^^ username:arguments[0], startDate:arguments[1], endDate:arguments[2] }).then((response) => { let categories = getCategories(response["transactions"]); console.log(categories); return categories; // <---- }).catch((err) => { console.log(err); }); } async function getCategories(transactions) { //^^^ let count = CATEGORIES; Object.keys(count).forEach(v => count[v] = 0); for (var i = 0; i < transactions.length; i++) { let transaction = transactions[i]; let response = await axios.post(SERVER_URL, { // ^^^^^^^^^^^^^^^^^^^^ transDescription: transaction["description"] }); let category = response.data["transactionCategory"]; console.log(category) count[category] += transaction["amount"]; } return count; }上还需要另一条注释：您的代码使该对象结构发生了变化。如果您第二次调用此函数并再次使用CATEGORIES，则可能是“危险的”：在这种情况下，以前的结果将被覆盖。每次初始化CATEGORIES时，实际上要复制一份会比较谨慎：

count

在循环和嵌套的Prom中发布请求

1 个答案: