read and write file in nodejs code example

Example 1: node js write file

// fs_write.js

const fs = require('fs');

// specify the path to the file, and create a buffer with characters we want to write
let path = 'ghetto_gospel.txt';
let buffer = new Buffer('Those who wish to follow me\nI welcome with my hands\nAnd the red sun sinks at last');

// open the file in writing mode, adding a callback function where we do the actual writing
fs.open(path, 'w', function(err, fd) {
    if (err) {
        throw 'could not open file: ' + err;
    }

    // write the contents of the buffer, from position 0 to the end, to the file descriptor returned in opening our file
    fs.write(fd, buffer, 0, buffer.length, null, function(err) {
        if (err) throw 'error writing file: ' + err;
        fs.close(fd, function() {
            console.log('wrote the file successfully');
        });
    });
});

Example 2: javascript write to file

<script> 
// Requiring fs module in which 
// writeFile function is defined. 
const fs = require('fs') 
  
// Data which will write in a file. 
let data = "Learning how to write in a file."
  
// Write data in 'Output.txt' . 
fs.writeFile('Output.txt', data, (err) => { 
      
    // In case of a error throw err. 
    if (err) throw err; 
}) 
</script>