how to export a string as a file and select a location in nodejs code example

Example 1: 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!');
});

Example 2: writefile in node js

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