I am a beginner to the nodejs. When I type the below, the code error occurs like this:
TypeError [ERR_INVALID_CALLBACK]: Callback must be a function
var fs = require('fs');
fs.readFile('readMe.txt', 'utf8', function (err, data) {
fs.writeFile('writeMe.txt', data);
});
Fs.writeFile()
according to the documentation here takes (
file, data[, options]and callback ) params so your code will be like this :
var fs = require('fs');
fs.readFile('readMe.txt', 'utf8', function (err, data) {
fs.writeFile('writeMe.txt', data, function(err, result) {
if(err) console.log('error', err);
});
});
fs.writeFile(...)
requires a third (or fourth) parameter which is a callback function to be invoked when the operation completes. You should either provide a callback function or use fs.writeFileSync(...)
See node fs docs for more info.
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