Node.js stringDecoder.write() Method

The stringDecoder.write() method in Node.js is used to decode data from a Buffer, TypedArray, or DataView into a string. It helps correctly process character data by handling incomplete multibyte characters across multiple chunks.

Stores incomplete multibyte characters in an internal buffer.
Uses the stored bytes in subsequent write() or end() calls.
Commonly used when reading data from streams in chunks.

Syntax:

stringDecoder.write( buffer )

where,

buffer: It is a Buffer, TypedArray or DataView that contains the bytes that have to be decoded.

Return Value: It returns a string which is decoded from the given buffer.

Example 1:

javascript

// Node.js program to demonstrate the   
// stringDecoder.write() Method 

// Import the string_decoder module
// and get the StringDecoder class 
// using object destructuring
const { StringDecoder } = require("string_decoder");

// Create a new instance of the decoder
const decoder = new StringDecoder("utf-8");

const text_one = Buffer.from("GeeksforGeeks", "utf-8");
let decoded_text = decoder.write(text_one);
console.log("Decoded Text:", decoded_text);

In this code, A StringDecoder object is created with UTF-8 encoding to decode data stored in a Buffer. The write() method converts the buffer content into a readable string and returns the decoded result.

Output:

Example 2:

javascript

// Node.js program to demonstrate the   
// stringDecoder.write() Method 

// Import the string_decoder module
// and get the StringDecoder class 
// using object destructuring
const { StringDecoder } = require("string_decoder");

// Create a new instance of the decoder
const decoder = new StringDecoder("utf-8");

// Decoding text using hex from buffer
const hex_text = new Buffer.from(
      "4765656B73666F724765656B73", "hex");
let decoded_hex_text = decoder.write(hex_text);
console.log("Decoded Text Hex:", decoded_hex_text);

// Decoding text using base64 from buffer
const base64_text = new Buffer.from(
      "R2Vla3Nmb3JHZWVrcw==", "base64");
let decoded_base64_text = decoder.write(base64_text);
console.log("Decoded Text Base64:", decoded_base64_text);

// Decoding the cent symbol from buffer
const cent_symbol = Buffer.from([0xc2, 0xa2]);
let cent_symbol_out = decoder.write(cent_symbol);
console.log("Cent Symbol:", cent_symbol_out);

In this code, The StringDecoder object is used to decode data stored in buffers with different encodings. It converts hexadecimal, Base64, and byte-based buffer data into readable UTF-8 text and symbols.

Output:

Use cases of stringDecoder.write()

Reading text files chunk by chunk without corrupting characters.
Processing incoming data from sockets and network connections.
Decoding hexadecimal and Base64 encoded buffer data.
Displaying human-readable text from binary data sources.
Handling Unicode characters that may be split across data chunks.

Reference: https://nodejs.org/api/string_decoder.html#string_decoder_stringdecoder_write_buffer

Node.js stringDecoder.write() Method

Use cases of stringDecoder.write()

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