NPM模块异步回报。获得从以前的函数值

Question

NPM安装异步

例子：

var async = require('async'); 
    var a = function(callback) 
    { 
     console.log("Hello "); 
     callback(null,'vals1') 
     return 'prop' 
    }; 
    var b = function(callback) 
    { 
     //I want get return 'prop' from a() its posible ? 
     console.log("World"); 
     callback(null,"vals2") 
    }; 
    async.series(
    [ 
     a,b 
    ],function(err,vals){ 
     console.log(vals) //[val1,vals2] 
     console.log('finals') 
    } 
     ); 

我希望得到回报 '托' 从（）到B（）。它的可能性？ 谢谢...

Answer 1

// Pretend this is some complicated async factory 
async.waterfall([ 
    function(callback){ 
     console.log('1'); 
     callback(null, 'one', 'two'); 
    }, 
    function(arg1, arg2, callback){ 
     console.log('2::::::' + arg1 + arg2 +':::') 
     // arg1 now equals 'one' and arg2 now equals 'two' 
     callback(null, 'three'); 
    }, 
    function(arg1, callback){ 
     // arg1 now equals 'three' 

     console.log('3::::::' + arg1) 
     callback(null, 'done'); 
    } 
], function (err, result) { 
    console.log(result); 
});