What is Node.js StringDecoder ?

The Node.js StringDecoder is used to decode buffer into string. It is similar to buffer.toString() but provides extra support to UTF.

You need to use require('string_decoder') to use StringDecoder module.

1. const StringDecoder = require('string_decoder').StringDecoder;  

Node.js StringDecoder Methods

StringDecoder class has two methods only.

Method	Description
decoder.write(buffer)	It is used to return the decoded string.
decoder.end()	It is used to return trailing bytes, if any left in the buffer.

Node.js StringDecoder Example

Let's see a simple example of Node.js StringDecoder.

File: stringdecoder_example1.js

1. const StringDecoder = require('string_decoder').StringDecoder;  
2. const decoder = new StringDecoder('utf8');  
3.   
4. const buf1 = new Buffer('this is a test');  
5. console.log(decoder.write(buf1));//prints: this is a test  
6.   
7. const buf2 = new Buffer('7468697320697320612074c3a97374', 'hex');  
8. console.log(decoder.write(buf2));//prints: this is a test  
9.   
10. const buf3 = Buffer.from([0x62,0x75,0x66,0x66,0x65,0x72]);  
11. console.log(decoder.write(buf3));//prints: buffer