node.js - Foreach 数组并在回调中使用数组成员

Question

这个问题已经有答案了:

Getting Coffeescript to create a local variable in a FOR loop (1 个回答)

已关闭 9 年前。

我有远程文件地址数组。我只是在 foreach 数组中使用 for ，并在 foreach 的主体中，启动 HTTP GET 请求来下载数据。但一切都是异步的，我需要知道文件名才能在请求回调中保存文件。

解决这个问题的最佳实践是什么？

演示代码:

files = ["url.com/file.png", "url.com/file.doc"]

for file in files
  req = http.get file, (response) =>
    response.setEncoding 'binary'
    body = ""

    response.on "data", (chunk) =>
      body += chunk

    response.on "end", () =>
      #Here I needs to know the file name to save it
      fs.writeFileSync @currentFolder + "/Files/" + file, body, "binary"

谢谢!

Answer 1

你必须确定它的范围。使用这样的函数:

files = ["url.com/file.png", "url.com/file.doc"]

for file in files
    ((file) ->
        req = http.get file, (response) =>
            response.setEncoding 'binary'
            body = ""

        response.on "data", (chunk) =>
            body += chunk

        response.on "end", () =>
            fs.writeFileSync @currentFolder + "/Files/" + file, body, "binary"
    ).call @, file