Node.js Buffer.readInt8() Method

The Buffer.readUInt8() method is used to read an unsigned 8-bit integer from a Buffer from a with the specific offset. Syntax:

Buffer.readInt8( offset )

Parameters: This method accepts single parameter offset which represents the number of bytes to skip before starting to read. The value of offset lies between the range 0 to buffer.length – 1. Its default value is 0. Return Value: This method returns the 8-bit signed integer value at specified offset. Example 1: javascript

// Node.js program to demonstrate the
// buffer.readUInt8() method
const value = Buffer.from([ -2, 3 ]);

// Reads the first value
console.log(value.readInt8(0));

// Reads the second value
console.log(value.readInt8(1));

// Throws an error
console.log(value.readInt8(2));

Output:

-2
3
RangeError [ERR_OUT_OF_RANGE]: The value of "offset" is out of range.

Example 2 javascript

// Node.js program to demonstrate the
// buffer.readUInt8() method
const obj = Buffer.from([ 0X52, 0X40, 0X78 ]);

// It returns the first value
console.log(obj.readUInt8(0));

// It returns the third value
console.log(obj.readUInt8(2));
const temp = Buffer.from("XYZ");

// It returns the ASCII value of capital 'X'
console.log(temp.readUInt8(0));

Output:

82
120
88

Note: Integers that reads from the Buffer are illustrated as two's complement signed values. Reference: https://nodejs.org/api/buffer.html#buffer_buf_readint8_offset