async 异步循环

async 异步循环

let async = require('async');let arr  = [{id: 1, age: 2},{id: 2, age: 3}, {id: 3, age: 4}
];function print(obj, cb) {if(obj.id === 2) {cb("it's a err")}else {console.log("print ->" + obj.id);cb(null)}
}async.mapSeries(arr,function(obj, callback){print(obj, function(err) {callback(err, obj);})}, function(err, ret){console.log(err, ret);});//print ->1
//it's a err [ { id: 1, age: 2 }, { id: 2, age: 3 } ]async.eachSeries(arr,function(obj, callback){print(obj, function(err) {callback(err);})}, function(err){console.log(err);});//print ->1
//it's a errasync.each(arr, function(obj, callback) {print(obj, function(err) {callback(err);})}, function(err){console.log(err);});//print ->1
//it's a err
//print ->3