在 while 循环中多次调用函数

发布于 2025-01-16 22:32:53 字数 1255 浏览 2 评论 0原文

我正在尝试从函数调用中获取数据，并将其保留在 while 循环中，这样如果未收到数据，该函数将被一次又一次地调用。我对数据的意思是我从 getData 函数返回的 data1、data2 和 data3 数组应该被填充并且不具有空值。但我无法找到解决方案。

这是我的代码：

router.get('/someurl' , async(req,res) => {
let data = [];
while(data.length == 0)
{
  data = await functionCall()
  console.log(data)
   }
})

这是我的 functionCall 代码的格式：

const unirest = require("unirest");
const cheerio = require('cheerio')





const getData = async() => {
   const data1 = [] , data2 = [] , data3 = [] ;
   try {
   const response = await unirest
   .get('url')
   .headers({'Accept': 'application/json', 'Content-Type': 'application/json'})
   .proxy("proxy")
   const $ = cheerio.load(response.body)
   $('hided').each((i,el) =>
   {
         data1[i] = $(el)
         .find('hided')
         .text()
         data2[i] = $(el)
         .find('hided')
   })
   $('hided').each((i,el) =>
   {
         data3[i] = $(el)
         .find('hided')
         .text()
   })
    if(data1.length && data2.length && data3.length))
    {
      return [data1 , data2 , data3]
    }
   }
      catch(error)
      {
         console.log("Error" , error);
      }
      return [];
      }
 
 
module.exports =  getData

原文

I am trying to get data from a function call and I am keeping it in a while loop so the function will be called again and again if data is not received. What I meant with the data is the data1,data2 and data3 arrays that I have returned from the getData function should be populated and not have a null value. But I am not able to find the solution.

Here is my code :

router.get('/someurl' , async(req,res) => {
let data = [];
while(data.length == 0)
{
  data = await functionCall()
  console.log(data)
   }
})

And here is the format of my functionCall code :

const unirest = require("unirest");
const cheerio = require('cheerio')





const getData = async() => {
   const data1 = [] , data2 = [] , data3 = [] ;
   try {
   const response = await unirest
   .get('url')
   .headers({'Accept': 'application/json', 'Content-Type': 'application/json'})
   .proxy("proxy")
   const $ = cheerio.load(response.body)
   $('hided').each((i,el) =>
   {
         data1[i] = $(el)
         .find('hided')
         .text()
         data2[i] = $(el)
         .find('hided')
   })
   $('hided').each((i,el) =>
   {
         data3[i] = $(el)
         .find('hided')
         .text()
   })
    if(data1.length && data2.length && data3.length))
    {
      return [data1 , data2 , data3]
    }
   }
      catch(error)
      {
         console.log("Error" , error);
      }
      return [];
      }
 
 
module.exports =  getData

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青瓷清茶倾城歌 2025-01-23 22:32:53

首先删除 if 语句，因为它实际上是 while 循环正在执行的操作。然后删除await，因为这不在异步函数中，并且它会出错。

回复收藏 0 原文

故人如初 2025-01-23 22:32:53

尝试这样的事情。

const fetchData = async ()=>{
data = await functionCall()
if(data.length==0){
fetchData()
}else{
return}
}

Try something like this.

const fetchData = async ()=>{
data = await functionCall()
if(data.length==0){
fetchData()
}else{
return}
}

回复收藏 0 原文

闻呓 2025-01-23 22:32:53

假设 fetchData 是一个 API 调用，则没有理由最初定义 data。您可以只记录调用该 API 的结果，直到结果为空数组为止。

const data = [1, 2, 3, 4];

// A simple API that returns a reduced array
// on every call
function mockApi() {
  return new Promise(res => {
    setTimeout(() => {
      res([...data]);
      data.shift();
    }, 1000);
  });
}

// Call the API, and if the the response
// has zero length log "No data" otherwise
// log the data, and call the function again.
async function fetchData() {
  const data = await mockApi();
  if (!data.length) {
    console.log('No data');
  } else {
    console.log(data);
    fetchData();
  }
}

fetchData();

Assuming that fetchData is an API call there's no reason to initially define data. You can just log the results of calling that API until the results are an empty array.

const data = [1, 2, 3, 4];

// A simple API that returns a reduced array
// on every call
function mockApi() {
  return new Promise(res => {
    setTimeout(() => {
      res([...data]);
      data.shift();
    }, 1000);
  });
}

// Call the API, and if the the response
// has zero length log "No data" otherwise
// log the data, and call the function again.
async function fetchData() {
  const data = await mockApi();
  if (!data.length) {
    console.log('No data');
  } else {
    console.log(data);
    fetchData();
  }
}

fetchData();

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