Writable Streams

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 LEARN NODE.JS

Writable Streams

In the previous exercise, we were reading data from a stream, but we can also write to streams! We can create a writeable stream to a file using the fs.createWriteStream() method:

const fs = require('fs')

const fileStream = fs.createWriteStream('output.txt');

fileStream.write('This is the first line!'); 
fileStream.write('This is the second line!');
fileStream.end();

In the code above, we set the output file as output.txt. Then we .write() lines to the file. Unlike a readable stream, which ends when it has no more data to read, a writable stream could remain open indefinitely. We can indicate the end of a writable stream with the .end() method.

Let’s combine our knowledge of readable and writable streams to create a program which reads from one text file and then writes to another.

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