Nodejs功能在操作完成前返回

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如何解决Nodejs功能在操作完成前返回？

我有一个关于我的 NodeJs 程序的问题。我有一个 FindItemFromUrlList 函数，它在 for 循环中调用另一个 Testurl。我希望 FindItemFromUrlList 在所有 url 都经过测试后返回找到的 url（因此列表 foundUrls）。但是当遍历 for 循环并测试并找到 url 时，当我执行 console.log (foundUrls) 时，我在 Testurl 中有一个空列表。我可以看到已经找到了 Urls，并且我认为算法在 for 循环之前执行了 console.log 函数，我尝试执行 .then 但它不起作用。

function FindItemFromUrlList(KeyworList,UrlList,color,Excludedurls){
    var completed_requests = 0 ;
    var itemfound = 0;
    foundUrls = [];
    for(urls of UrlList){
        completed_requests++;
        Testurl(KeyworList,urls,itemfound,completed_requests,foundUrls,Excludedurls);
    }
    console.log(foundUrls);
}

function Testurl(KeyworList,Excludedurls){
    https.get(urls,function (res) {
        var HTMLcode2 = "";
        res.on('data',(d) => {
            HTMLcode2 += d;
        })
            .on('end',() => {
                for (keyword of KeyworList) {
                    if (HTMLcode2.toString().includes(keyword) && !foundUrls.includes(urls) && (!(Excludedurls && urls.includes(Excludedurls))) ){
                        foundUrls.push(urls);
                    }
                }
                if (completed_requests == UrlList.length) {
                    // All download done,process responses
                    console.log("Done all requests");
                    console.log("nombre d'items trouvés : ",foundUrls.length);
                    console.log("Url trouvées :",foundUrls);
                }
            })})
}

这是我的代码运行的结果：

[]
Done all requests
nombre d'items trouvés :  5
Url trouvées : [
  'https://www.supremenewyork.com/shop/tops-sweaters/jmqsjoxe5/iuawc8jf5','https://www.supremenewyork.com/shop/tops-sweaters/jmqsjoxe5/if60rct4l','https://www.supremenewyork.com/shop/tops-sweaters/jmqsjoxe5/dgkjtbima','https://www.supremenewyork.com/shop/tops-sweaters/jmqsjoxe5/wwx6gdai0','https://www.supremenewyork.com/shop/tops-sweaters/jmqsjoxe5/x2y3lk890'
]

解决方法

async function FindItemFromUrlList(KeyworList,UrlList,Color,Excludedurls){
    var completed_requests = 0 ;
    var itemfound = 0;
    const promises = []
    foundUrls = [];
    for(urls of UrlList){
        completed_requests++;
        const promises = Testurl(KeyworList,urls,itemfound,completed_requests,foundUrls,Excludedurls);
       promises.push(promisE)
    }
    
    await Promise.all(promises) // this will wait for promises to resolve
    console.log(foundUrls);
}

async function Testurl(KeyworList,Excludedurls) {
  return new Promise((resolve,reject) => {
    https.get(urls,function (res) {
        var htmlcode2 = "";
        res.on('data',(d) => {
            htmlcode2 += d;
        })
            .on('end',() => {
                for (keyword of KeyworList) {
                    if (htmlcode2.toString().includes(keyword) && !foundUrls.includes(urls) && (!(Excludedurls && urls.includes(Excludedurls))) ){
                        foundUrls.push(urls);
                    }
                }

                resolve() // here you resolve the promise

                if (completed_requests == UrlList.length) {
                    // All download done,process responses
                    console.log("Done all requests");
                    console.log("nombre d'items trouvés : ",foundUrls.length);
                    console.log("Url trouvées :",foundUrls);
                }
            })})
  })
    
}

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