節點js異步回調問題

Question

我對異步瀑布有點問題，因爲我想在循環處理的函數之後調用下一個函數。腳本是異步瀑布流的一部分，以前的函數工作得很好。這裏唯一的事情是，它有一個用於loop.The代碼below.Any幫助將是非常appreciated.Thanks

function(querySize,req) 
{ 
console.log("in second function call :" +querySize); 
var temp,title; 
for(var counter = 0;counter <= querySize;counter++) 
{ 
    websiteAddressArray[counter] = req.query.address[counter]; 
    console.log("for is : " +req.query.address[counter]); 
    console.log("first line is : " +websiteAddressArray[counter]); 
    console.log("second line is : " +websiteAddressArray[counter]); 
    request(websiteAddressArray[counter], function(err, resp, body) 
    { 
     $ = cheerio.load(body); 
     console.log("title is : " +$('title').text()); 
     titleArray[counter] = $('title').text(); 
    }); 
    } 
    var line="this is string"; 
    callback(null,line); 
}, 
function(callback,line) 
{ 
    console.log("line is : " +line) 
}, 

Answer 1

你syntax是不正確的。總是通過callback最後一個參數async.waterfall

function(querySize, req,callback) { 
    console.log("in second function call :" + querySize); 
    var temp, title; 
    for (var counter = 0; counter <= querySize; counter++) { 
    websiteAddressArray[counter] = req.query.address[counter]; 
    console.log("for is : " + req.query.address[counter]); 
    console.log("first line is : " + websiteAddressArray[counter]); 
    console.log("second line is : " + websiteAddressArray[counter]); 
    request(websiteAddressArray[counter], function(err, resp, body) { 
     $ = cheerio.load(body); 
     console.log("title is : " + $('title').text()); 
     titleArray[counter] = $('title').text(); 
    }); 
    } 
    var line = "this is string"; 
    callback(null, line); 
}, 
function(callback, line) { 
    console.log("line is : " + line) 
},