files.forEach（function（file）{^ TypeError：无法读取未定义的属性'forEach'

Question

var testFolder = '/zip_file\ /sit1_Wave2_Settlement_afx_formula\ \
(1\)/data_dictionary/CM.173/';
   var fs = require('fs');
      fs.readdir(testFolder, (err, files) => {
        files.forEach(file => {
    console.log(file);

});
})

I need to read a file contents, if i execute the above code it shows an error.

files.forEach(function(file) {
   ^

TypeError: Cannot read property 'forEach' of undefined

Answer 1

You should check for errors before trying to read the files, and then check to see if the files object is defined, like this:

fs.readdir(testFolder, (err, files) => {
    if (err) throw err;
    if (files){
        files.forEach(file => {
            console.log(file);
        });
    } else {
        console.log('no files found')
    }
});