Node.JS Write to File

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Node.JS Write to File

Node.JS Write to File

Node.JS Write to File – To write content to a file in Node.js, usewriteFile() function of node fs module.

Syntax of writeFile
Example 1
Example 2 – With encoding mentioned

Syntax of Node.js writeFile() function

fs = require('fs');

fs.writeFile(filename, data, [encoding], [callback_function])

filename : [mandatory] name of the file, the data has to be written to data : [mandatory] content that has to be written to file encoding : [optional] encoding standard that has to be followed while writing content to file. callback_function : [optional] function that would be called once writing to the file is completed

Allowed encoding formats are

ascii
utf8
base64

Note : A new file with specified filename is created with data specified. If a file with the same name exists already, the content is overwritten. Care has to be taken as previous content of file could be lost.

Example 1 – Write data to file in Node.js

In this example, we shall write content, “Hello !” , to a text file sample.txt.

// include file system module

var fs = require('fs');

var data = "Hello !"

// write data to file sample.html

fs.writeFile('sample.txt',data,

// callback function that is called after writing file is done

function(err) {

if (err) throw err;

// if no error

console.log("Data is written to file successfully.")

});

When the above program is run in Terminal,

arjun@arjun-VPCEH26EN:~/workspace/nodejs$ node nodejs-write-to-file-example.js

Data is written to file successfully.

Example 2 – Write Content to file with specified encoding

// include file system module

var fs = require('fs');

var data = "HELLO";

// write data to file sample.html

fs.writeFile('sample.txt',data, 'ascii',