node.js - 在没有 IO 操作的情况下，return 在 node.js 中是否可以正常工作？

Question

例如，我的功能是这样的

function summ(a,b)
{
 return a+b;
}

module.exports.summ = summ;

在其他文件中：

var obj = require('./that file')

function app()
{
 var s = obj.summ(7,7);
}

如果我console.log(s); 说它给出了完美的答案。我怀疑这是否会在请求频繁出现时一直出现，因为我在休息 api 中使用这种返回？或者需要回调函数，结果是

function summ(a,b,callback)
{
 callback(a+b);
}

和

function app()
{
 obj.summ(7,7,function(result){
 var s = result;
  }
 }

Answer 1

As long as your summ function behaves in a synchronous manner, like it does in your example code, you don't have to use callbacks.

If you would use asynchronous functions in summ (anything I/O related, like reading a file, querying a database, opening a network connection), that would require passing a callback function because you would have to wait until the action is completed before you return the result (by calling the callback function).