Node.js Buffer.readUInt16BE() Method (original) (raw)

Last Updated : 13 Oct, 2021

The Buffer.readUInt16BE() method is an inbuilt application programming interface of class Buffer within the Buffer module which is used to read 16-bit value from an allocated buffer at a specified offset.Syntax:

Buffer.readUInt16BE( offset )

Parameters: This method accepts single parameter offset that specifies the number of bytes to skip before read or simply signify the index in the buffer. The value of buffer lies 0 <= offset <= Buffer.length - 2. Its default value is 0.Return Value: This method returns an unsigned 16-bit integer value that is read from buffer in big endian format (Buffer.readUInt16LE() read 16 bit in little endian format). Below examples illustrate the use of Buffer.readUInt16BE() method in Node.js:Example 1:

javascript `

// Node.js program to demonstrate the // Buffer.readUInt16BE() method

// Allocating buffer from array const buf = Buffer.from([0x21, 0x09, 0x19, 0x98]);

// Printing allocated buffer console.log(buf);

// Reading 16bits data from the buffer // and printing it as a string console.log(buf.readUInt16BE(0).toString(16)); console.log(buf.readUInt16BE(1).toString(16)); console.log(buf.readUInt16BE(2).toString(16));

`

Output:

<Buffer 21 09 19 98> 2109 919 1998

Example 2:

javascript `

// Node.js program to demonstrate the // Buffer.readUInt16BE() method

// Allocating buffer from array const buf = Buffer.from([0x21, 0x09, 0x19, 0x98]);

// Printing allocated buffer console.log(buf);

// Reading 16bits data from the buffer // and printing it as a string console.log(buf.readUInt16BE(0).toString(16)); console.log(buf.readUInt16LE(0).toString(16)); console.log(buf.readUInt16BE(1).toString(16)); console.log(buf.readUInt16LE(1).toString(16)); console.log(buf.readUInt16BE(2).toString(16)); console.log(buf.readUInt16LE(2).toString(16));

`

Output:

<Buffer 21 09 19 98> 2109 921 919 1909 1998 9819

Example 3:

javascript `

// Node.js program to demonstrate the // Buffer.readUInt16BE() method

// Allocating buffer from array const buf = Buffer.from([0x21, 0x09, 0x19, 0x98]);

// Printing allocated buffer console.log(buf);

// Reading 16bits data from the buffer // and printing it as a string console.log(buf.readUInt16BE(0).toString(16)); console.log(buf.readUInt16BE(1).toString(16)); console.log(buf.readUInt16BE(2).toString(16));

// Wrong index is provided to produce error console.log(buf.readUInt16BE(3).toString(16));

`

Output:

<Buffer 21 09 19 98> 2109 919 1998 internal/buffer.js:49 throw new ERR_OUT_OF_RANGE(type || 'offset', ^ RangeError [ERR_OUT_OF_RANGE]: The value of "offset" is out of range. It must be >= 0 and <= 2. Received 3 at boundsError (internal/buffer.js:49:9) at Buffer.readUInt16BE (internal/buffer.js:215:5) . . .

Note: The above program will compile and run by using the node index.js command.Reference: https://nodejs.org/api/buffer.html#buffer_buf_readuint16be_offset