JAVASCRIPT

fs.writefile

const fs = require('fs');

fs.writeFile("/tmp/test", "Hey there!", function(err) {
    if(err) {
        return console.log(err);
    }
    console.log("The file was saved!");
}); 

// Or
fs.writeFileSync('/tmp/test-sync', 'Hey there!');

writefile in node js

// append_file.js

const fs = require('fs');

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

writefile in node js

fs.writeFile('2pac.txt', 'Some other lyric', 'ascii', callback);