Question

在使用API和Promise方面，我是一个很大的新手-因此，我很难解决这个问题。

目标是向API发出GET请求并返回这些结果。但是，由于API将数据分布在多个页面上，因此我将遍历API页面，直到返回0个列表。

我能够成功地将列表记录到控制台，但是，即使listsExist设置为false，loopThroughListings内部的while循环也似乎从未关闭。

我哪里出错了？

const axios = require('axios');

// Loop through multiple pages of listings in the API
function loopThroughListings() {
  let listingsExist = true;

  // Loop through listings until they don't exist
  while(listingsExist) {

    getListing().then(function(listing) {

      if(listing.length < 1 ) {
        // if listings don't exist, stop the loop
        // THIS IS WHERE THE ISSUE IS
        console.log("No Listings");
        listingsExist = false;
      } else {
        // if listings do exist, log them to console
        console.log(listing);
      }

    });

  }
}

// Return listing data from API
async function getListing(page) {
  try {
    const response = await axios.get(`https://mlb19.theshownation.com/apis/listings.json?type=Stadium&page=1}`);
    return response.data.listings;
  } catch (error) {
    console.error(error);
  }
}

loopThroughListings();

Answer 1

您需要先将loopThroughListings设置为async，然后才能await getListing()

像这样：

const axios = require('axios');

// Loop through multiple pages of listings in the API
async function loopThroughListings() {
    let listingsExist = true;

    // Loop through listings until they don't exist
    while (listingsExist) {
        const listing = await getListing();
        if (listing.length < 1) {
            // if listings don't exist, stop the loop
            // THIS IS WHERE THE ISSUE IS
            console.log("No Listings");
            listingsExist = false;
        } else {
            // if listings do exist, log them to console
            console.log(listing);
        }
    }
}

// Return listing data from API
async function getListing(page) {
    try {
        const response = await axios.get(`https://mlb19.theshownation.com/apis/listings.json?type=Stadium&page=1}`);
        return response.data.listings;
    } catch (error) {
        console.error(error);
    }
}

loopThroughListings();

就个人而言，因为while循环当然至少会运行一次，所以我改用do/while-对我来说，这使代码的流程更加明显

    do {
        const listing = await getListing();
        if (listing.length < 1) {
            // if listings don't exist, stop the loop
            // THIS IS WHERE THE ISSUE IS
            console.log("No Listings");
            listingsExist = false;
        } else {
            // if listings do exist, log them to console
            console.log(listing);
        }
    } while(listingsExist);

但这只是一个见解

发出Axios GET请求时出现无限循环-循环不会关闭

1 个答案: