使用node.js的递归模式循环

var @R_772_10613@est = @R_772_10613@ire('@R_772_10613@est');
var fs = @R_772_10613@ire('fs');
var arr = ['glasgow','preston','blackpool','chorley','newcastle','bolton','paris','york','doncaster'];
//the function I want to call on each city from [arr]
function getTravelTime(a,b,callBACk){
 @R_772_10613@est('https://maps.googleapis.com/maps/api/directions/json?origin='+a+'&desTination='+b+'&region=en&sensor=false',function(err,res,data){
 var foo = JSON.parse(data);
 var duration = foo.routes[0].legs[0].duration.text;
 console.log(duration);
 });
};

function show(b){
 fs.writeFile('tesTing.txt',b);
};


function uploader(i){
 if( i < arr.length ){
   show( arr[i],function(){
   uploader(i+1);
   });
 }
}
uploader(0)

解决方法@H_197_13@

我也遇到过这样的问题,所以我编写了一个递归回调函数,它将作为for循环,但你可以控制何时递增.以下是该模块,名称为syncFor.js并将其包含在您的程序中

@H_374_7@module.exports = function syncFor(index,len,status,funC) { func(index,function (res) { if (res == "next") { index++; if (index < len) { syncFor(index,"r",func); } else { return func(index,"done",function () { }) } } }); } //this will be your program if u include this module var @R_772_10613@est = @R_772_10613@ire('@R_772_10613@est'); var fs = @R_772_10613@ire('fs'); var arr = ['glasgow','doncaster']; var syncFor = @R_772_10613@ire('./syncFor'); //syncFor.js is stored in same directory //the following is how u implement it syncFor(0,arr.length,"start",function (i,call) { if (status === "done") console.log("array iteration is done") else getTravelTime(arr[i],"whatever",function () { call('next') // this acts as increment (i++) }) }) function getTravelTime(a,callBACk) { @R_772_10613@est('https://maps.googleapis.com/maps/api/directions/json?origin=' + a + '&desTination=' + b + '&region=en&sensor=false',function (err,data) { var foo = JSON.parse(data); var duration = foo.routes[0].legs[0].duration.text; callBACk(); // call the callBACk when u get answer console.log(duration); }); };