[英]How to send result of a function after the loop is finished?
In a Node/Express server in CoffeeScript, I have the following function : 在CoffeeScript的Node / Express服务器中,我有以下功能:
@resolveServers = (url, servers, answer) ->
result = []
treatServer(url, server, (treatAnswer) ->
result.push(treatAnswer)
) for server in servers
answer(result)
The treatServer method take some times, and the answer is send before the loop is finish. treatServer方法需要一些时间,并且在循环结束之前发送答案。 How can I send the result only when the loop is come at an end ?
如何在循环结束时才发送结果?
Thanks for the help. 谢谢您的帮助。
It is easy as long as you know the number of servers beforehand: 只要您事先知道服务器的数量,这很容易:
@resolveServers = (url, servers, answer) ->
result = []
count = 0
treatServer(url, server, (treatAnswer) ->
result.push(treatAnswer)
count++
answer result if count is servers.length
) for server in servers
Edit: After thinking about it again. 编辑:再次考虑之后。 In your case this could be solved even easier:
在您的情况下,这可以更容易解决:
@resolveServers = (url, servers, answer) ->
result = []
treatServer(url, server, (treatAnswer) ->
result.push treatAnswer
answer result if result.length is servers.length
) for server in servers
Edit 2: As squint pointed out, that push returns the length of the array: 编辑2: 斜视指出,该推送返回数组的长度:
@resolveServers = (url, servers, answer) ->
result = []
treatServer(url, server, (treatAnswer) ->
answer result if result.push(treatAnswer) is servers.length
) for server in servers
If you want to maintain readability of the code, the last edit might not be the best choice ;-) 如果你想保持代码的可读性,最后的编辑可能不是最好的选择;-)
You can also use async module 您也可以使用异步模块
Here is great article Node.js async in practice: When to use what? 这是伟大的文章Node.js在实践中的异步:何时使用什么? which explains async in details.
这解释了async的细节。
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