how to write a message on a file in node js code example

Example 1: writefile in node js

// write_stream.js

const fs = require('fs');

let writeStream = fs.createWriteStream('secret.txt');

// write some data with a base64 encoding
writeStream.write('aef35ghhjdk74hja83ksnfjk888sfsf', 'base64');

// the finish event is emitted when all data has been flushed from the stream
writeStream.on('finish', () => {
    console.log('wrote all data to file');
});

// close the stream
writeStream.end();

Example 2: writefile in node js

// append_file.js

const fs = require('fs');

// add a line to a lyric file, using appendFile
fs.appendFile('empirestate.txt', '\nRight there up on Broadway', (err) => {
    if (err) throw err;
    console.log('The lyrics were updated!');
});