错误：无法读取未定义的属性'forEach'

Question

我尝试读取未格式化的文档，然后以好格式重写它，但是当执行下面的代码时，我尝试了 我收到了一个错误Cannot read property 'forEach' of undefined（下面的完整错误）。 我不明白为什么会发生这种错误以及如何解决它。

CODE

const testFolder = '/zip_file\ /sit1_Wave2_Settlement_afx_formula\ \(1\)/data_dictionary/CM.173/'; 

var fs = require('fs'); 
var formatedcode = []; 
fs.readdir(testFolder, (err, files) => { 

    files.forEach(file => { 
     console.log(file); 
     var array = fs.readFileSync(testFolder + file).toString().split("\n"); 
     //console.log("\n\n\n",array); 
     var wstream = fs.createWriteStream(file); 

     for (i in array) { 
     var xml = array[i], 
     pp_xml = require('../pretty-data').pd.xml(xml); 
     formatedcode.push(pp_xml); 
     } 

     for (look in formatedcode) { 
     var wstream = fs.createWriteStream(file); 

     wstream.on('finish', function() { 
      console.log('file has been written'); 
     }); 

     wstream.write(formatedcode[look]); 
     wstream.end(); 
     } 
    }); 
}) 

错误

files.forEach(file => {^ 

TypeError: Cannot read property 'forEach' of undefined 
    at fs.readdir (C:\Users\Manoj kumar\Downloads\pretty-data\pretty-data\findingxml.js:5:6) 
    at FSReqWrap.oncomplete (fs.js:123:15) 

Answer 1

我已经做了一些修改你的代码。还有一些其他的东西需要注意，比如wstream被多次定义，这可能会导致意想不到的结果。

关于您的问题，请尝试以下;

files.forEach((file) => 
{ 
    console.log(file); 

为了方便起见，请查看完整的代码块;

const testFolder = '/zip_file\ /sit1_Wave2_Settlement_afx_formula\ \(1\)/data_dictionary/CM.173/'; 

var fs = require('fs'); 
var formatedcode = []; 
fs.readdir(testFolder, (err, files) => { 

    files.forEach((file) => 
    { 
     console.log(file); 

     var array = fs.readFileSync(testFolder + file).toString().split("\n"); 
     //console.log("\n\n\n",array); 

     var wstream = fs.createWriteStream(file); 
     for (var i in array) { 
      var xml = array[i], 

       pp_xml = require('../pretty-data').pd.xml(xml); 
      formatedcode.push(pp_xml); 

     } 
     for (var look in formatedcode) { 
      wstream = fs.createWriteStream(file); 
      wstream.on('finish', function() { 
       console.log('file has been written'); 
      }); 
      wstream.write(formatedcode[look]); 
      wstream.end(); 
     } 
    }); 
});