To add to the end or append data to a file in Node.js, you can use the appendFile()
asynchronous function from the fs
(filesystem) module.
/*🔥 Append data to a file 🔥 */
fs.appendFile("file.txt", "Hello World!", "utf-8");
For example, Consider a file called logs.txt
in which we have some log data and we want to add additional data to the end of the file.
// name of file
const file = "logs.txt";
// logs
const logData = "Request status: 200 OK";
Now let's use the appendFile()
asynchronous function and pass:
- the
path of the file
to append data as the first argument - the
data
as the second argument - the
encoding
as the third argument - and a
callback function
to execute after the data is successfully added to the file.
It can be done like this,
// require fs module
const fs = require("fs");
// name of file
const file = "logs.txt";
// logs
const logData = "\nRequest status: 200 OK";
// add logData to end of logs.txt file
// using fs.appendFile() asynchronous function
fs.appendFile(file, logData, "utf-8", () => {
console.log("Log data added!");
});
And we have successfully added data to the end of the file! 🔥.
See this example live in repl.it.