1. Day 1 - The Beginning
2. Day 2 - File System in node.js
3. Day 3 - Regular expressions in node.js
4. Day 4 - Console module in node.js
5. Day 5 - All about errors
6. Day 6 - Array methods
7. Day 7 - All about NPM
8. Day 8 - Publishing package on NPM
9. Day 9 - Crypto Module ( Hashing and HMAC)
10. Day 10 - Crypto Module ( Encryption and Decryption )
11. Day 11 - Express Framework
12. Day 12 - CRUD in MongoDB using node.js
13. Day 13 - Sign Up form in node.js
14. Day 14 - Introduction to socket.io
15. Day 15 - All about streams
16. Day 16 - Zlib Module
17. Day 17 - CRUD in MySQL using node.js
18. Day 18 - Concepts of callbacks in node.js
19. Day 19 - Query String in node.js
20. Day 20 - Timers in node.js
21. Day 21 - Buffers in node.js
22. Day 22 - String Decoder Module in node.js
23. Day 23 - Debugger module in node.js
24. Day 24 - Child Processes in node.js
25. Day 25 - Clusters in node.js
26. Day 26 - OS module in node.js
27. Day 27 - Assert module in node.js
28. Day 28 - Getting Tweets using node.js
29. Day 29 - Uploading file to dropbox using node.js
30. Day 30 - Github API with node.js

String decoder module in node.js is used to provide an API for decoding buffer object into strings. Also , this decoding is performed in a manner that UTF-8 and UTF-16 characters multibyte coding is preserved. We can require the query string module in the following way :

											
var sd = require('string_decoder').StringDecoder;
											
										

String decoder class has only 2 methods which are as follows :

1. stringDecoder.write(buffer) : This method is used to return the specified buffer as decoded string. We pass buffer as the argument in this method . An example is given below :
   

   											
   //name of the file : write.js
   var stringDecoder = require('string_decoder').StringDecoder;
   var sd = new stringDecoder('utf8');
   var buff = Buffer('data to be buffered');
   //Print the buffered data
   console.log(buff); 
   //Print the decoded buffer  
   console.log(sd.write(buff));
   											
   										

   
   We can run it in the following way :
   

   											
   >node write.js
   <Buffer 64 61 74 61 20 74 6f 20 62 65 20 62 75 66 66 65 72 65 64>
   data to be buffered
   											
   										

   
   
2. stringDecoder.end([buffer]) : This method is used to return the remaining of the input stored in internal buffer.

In this chapter of 30 days of node tutorial series, we learned about String decoder method in node.js which is used for decoding buffer object into strings. We also learned about two methods of string decoder which are stringDecoder.write(buffer) and stringDecoder.end([buffer]) .